US4771758A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air weapon with air compression system having grooves for air transfer
Assignee: THEOBEN Ltd
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Filing: 1986-04-01
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Granted: 1988-09-20
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Expires: 2006-04-01
Abstract
Abstract An air weapon air compression system of the type in which air is compressed in a cylinder and expelled through a discharge port, to propel a projectile along the barrel and fire it out of the weapon, by the rapid movement of a piston within the cylinder. Such a system incorporating grooves in one or both of opposed portions of the cylinder and piston, for the transfer of air towards the discharge port during the final compression stage, to enhance the performance of the weapon.
Inventors
- 👤 Hugh F. Taylor
- 👤 David R. Theobald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:43
CPC Classifications
F; F41; F41B; F41B11/00; F41B11/70; F41B11/73
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
207 words
In an air weapon provided with a barrel and a discharge port which is adapted to have compressed air expelled therethrough to propel a projectile along said barrel and out of said weapon, an air compression system for compressing said air, said air compression system comprising a cylinder, at least one piston slidably located within said cylinder, said at least one piston having a piston crown and said cylinder having an end wall opposed to said piston crown, said end wall defining said discharge port which opens into said cylinder; wherein the improvement comprises shallow groove means in the form of elongate depressions formed in the material of and generally parallel to, the plane of at least one of said opposed piston crown and said end wall, said groove means being open to the cylinder along their length, said groove means including at least one groove which is aligned at one point along the length thereof with said discharge port thereby providing direct communication between said groove and said discharge port to allow for the transfer of air towards the discharge port during a final compression stage of said air in said cylinder by said at least one piston thereby to enhance the performance of said weapon.
Claim 2
Dependent Claim
207 words
In an air weapon provided with a barrel and a discharge port which is adapted to have compressed air expelled therethrough to propel a projectile along said barrel and out of said weapon, an air compression system for compressing said air, said air compression system comprising a cylinder, at least one piston slidably located within said cylinder, said at least one piston having a piston crown and said cylinder having an end wall opposed to said piston crown, said end wall defining said discharge port which opens into said cylinder; wherein the improvement comprises shallow groove means in the form of elongate depressions formed in the material of and generally parallel to, the plane of at least one of said opposed piston crown and said end wall, said groove means being open to the cylinder along their length, said groove means including at least one groove which is aligned at one point along the length thereof with said discharge port thereby providing direct communication between said groove and said discharge port to allow for the transfer of air towards the discharge port during a final compression stage of said air in said cylinder by said at least one piston thereby to enhance the performance of said weapon.
Claim 3
Dependent Claim
30 words
An air compression system according to claim 1 wherein said groove means comprises a plurality of grooves in addition to said at least one groove formed in said piston crown.
Claim 4
Dependent Claim
26 words
An air compression system according to claim 1 wherein said groove means further comprises a plurality of grooves formed in said end wall of said cylinder.
Claim 5
Dependent Claim
46 words
An air compression system according to claim 1 wherein said groove means including said at least one groove comprises three grooves generally in the form of a star, the grooves being symmetrically arranged to radiate from a center point in the end of said piston crown.
Claim 6
Dependent Claim
59 words
An air compression system according to claim 1 wherein said groove means further comprises a recess formed in said piston crown at a position corresponding to the position of said discharge port in said end wall of said cylinder, and said at least one groove comprises a plurality of grooves radiating outwards from said recess in said piston crown.
Claim 7
Dependent Claim
46 words
An air compression system according to claim 1 wherein said piston crown incorporates a lubricant scraper on its end remote from said end of said cylinder, said scraper being adapted for wiping lubricant from a side wall of said cylinder upon movement of said piston crown.
Claim 8
Dependent Claim
64 words
An air compression system according to claim 1 including a resilient seal associated with said at least one piston and said cylinder, one part of said seal providing an air tight seal between said at least one piston and said cylinder during compression and another part of said seal providing a scraper for scraper lubricant from a cylindrical wall of said cylindrical during induction.
Claim 9
Dependent Claim
187 words
In an air weapon providing with a barrel and a discharge port which is adapted to have compressed air expelled therethrough to propel a projectile along said barrel and out of said weapon, an air compression system for compressing said air, said air compression system comprising a cylinder, and at least one piston slidably located within said cylinder, said at least one piston having a piston crown and said cylinder defining said discharge port which opens into said cylinder; wherein the improvement comprises shallow groove means in the form of elongate depressions formed in the material of and generally parallel to, the plane of said piston crown, said groove means being open to the cylinder along their length, said groove means including at least one groove which is aligned at one point along the length thereof with said discharge port thereby providing direct communication between said groove and said discharge port to allow for the transfer of air towards the discharge port during a final compression stage of said air in said cylinder by said at least one piston, thereby to enhance the performance of said weapon.
Claim 10
Dependent Claim
187 words
In an air weapon providing with a barrel and a discharge port which is adapted to have compressed air expelled therethrough to propel a projectile along said barrel and out of said weapon, an air compression system for compressing said air, said air compression system comprising a cylinder, and at least one piston slidably located within said cylinder, said at least one piston having a piston crown and said cylinder defining said discharge port which opens into said cylinder; wherein the improvement comprises shallow groove means in the form of elongate depressions formed in the material of and generally parallel to, the plane of said piston crown, said groove means being open to the cylinder along their length, said groove means including at least one groove which is aligned at one point along the length thereof with said discharge port thereby providing direct communication between said groove and said discharge port to allow for the transfer of air towards the discharge port during a final compression stage of said air in said cylinder by said at least one piston, thereby to enhance the performance of said weapon.
Claim 11
Dependent Claim
55 words
An air compression system according to claim 8 wherein said groove means further comprises a recess formed in said piston crown at a position corresponding to the position of said discharge port in said cylinder, and said at least one groove comprises a plurality of grooves radiating outwards from said recess in said piston crown.
Claim 12
Dependent Claim
50 words
An air compression system according to claim 8 wherein said piston crown incorporates a lubricant scraper around its perphery at a position which is axially spaced from said groove means, said scraper being adapted for wiping lubricant from a side wall of said cylinder upon movement of said piston crown.
Claim 13
Dependent Claim
64 words
An air compression system according to claim 8 including a resilient seal associated with said at least one piston and said cylinder, one part of said seal providing an air tight seal between said at least one piston and said cylinder during compression and another part of said seal providing a scraper for scraping lubricant from a cylindrical wall of said cylinder during induction.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-09-20 | 1992-03-21 | 1992-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-20 | 1996-03-21 | 1996-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-20 | 2000-03-21 | 2000-09-20 | $7700.00 | Window Closed / Lapsed |