Valve guide with external return spring for musical instrument
A piston valve for a brass-wind musical instrument has spring barrel in which are formed opposing first and second keyways. A valve stem screws onto the top of the spring barrel. A loose key extends transversely through the first and second keyways. A bottom ring is slidably disposed around the spring barrel. The bottom ring has opposing notches. The loose key acts as a cross-bar supporting the bottom ring in its notches from underneath and enabling the bottom ring a degree of independent movement. A return spring is captured between the bottom ring and a top ring at the valve step/spring barrel interface. The loose key has a generally rectangular cross-section with first and second protruding ends fit within the respective first and second keyways. The first protruding end can have a major T-shaped head, whereas the second protruding end may have a minor t-shaped head.
1. A piston valve for a brass-wind musical instrument comprising:
a generally cylindrical valve body having a top end and a bottom end, said valve body defining a central longitudinal axis along which reciprocating actuation of said piston valve occurs,
a generally cylindrical spring barrel extending between a base and a neck, said base in direct abutting contact with said top end of said valve body, a first keyway disposed in said spring barrel, a second keyway disposed in said spring barrel diametrically opposite said first keyway, each of said first and second keyways extending from said base axially toward respective terminal ends adjacent said neck,
a valve stem extending axially from said neck of said spring barrel,
a bottom ring slidably disposed around said spring barrel, said bottom ring having an annular rim,
a return spring disposed around said spring barrel, said return spring extending between upper and lower ends, said lower end seated against said annular rim of said bottom ring, and
a loose key extending transversely through said first and second keyways of said spring barrel, said loose key being in direct contact with and selectively moveable relative to said annular rim of said bottom ring.
2. The piston valve of claim 1 , wherein said lower cuff includes a pair of notches disposed diametrically opposite one another.
3. The piston valve of claim 2 , wherein said first keyway has a width, each said notch of said lower cuff having a width generally equal to said width of said first keyway.
4. The piston valve of claim 3 , wherein said loose key has a first protruding end in registry with said first keyway and a second protruding end in registry with said second keyway, said first and second protruding ends adapted to nest within said notches of said bottom ring.
5. The piston valve of claim 4 , wherein said first protruding end has a major T-shaped head.
6. The piston valve of claim 5 , wherein said first keyway has a generally constant width, said second keyway having a generally constant width, said width of said second keyway being smaller than said width of said first keyway, said major T-shaped head having a major width greater than said width of said first keyway.
7. The piston valve of claim 4 , wherein said second protruding end has minor t-shaped head, said minor t-shaped head having a minor width greater than said width of said second keyway.
8. The piston valve of claim 1 , wherein said rim of said bottom ring has an outer rim diameter and an inner rim diameter, said bottom ring including a lower cuff extending downwardly from said rim adjacent said inner rim diameter, said lower cuff set back from said outer rim diameter to form an annular ledge.
9. The piston valve of claim 8 , wherein said loose key has an overall length greater than said diameter of said outer rim diameter.
10. The piston valve of claim 1 , wherein said valve stem includes a coupling configured to connect to said neck of said spring barrel, a top ring captured between said coupling of said valve stem and said neck of said spring barrel.
11. The piston valve of claim 10 , wherein said spring barrel has a barrel diameter, said top ring having an annular upper flange, said upper flange having an outer diameter and an inner diameter, said outer diameter of said upper flange being greater than said barrel diameter, said inner diameter being smaller than said barrel diameter.
12. The piston valve of claim 11 , wherein said top ring includes a skirt extending downwardly from said upper flange, said skirt set back from said outer diameter of said upper flange to form an outer relief, said upper end of said return spring seated against said outer relief of said top ring.
13. The piston valve of claim 12 , wherein said skirt is set back from said inner diameter of said flange to form an inner relief, said inner relief configured to overlie said neck of said spring barrel and be compressed by said coupling of said valve stem.
14. A guide and return spring conversion kit for the piston valve of a brass-wind musical instrument, said conversion kit comprising:
a top ring having an annular upper flange, said upper flange having an outer diameter and an inner diameter, a skirt extending downwardly from said upper flange, said skirt set back from said outer diameter of said upper flange to form an outer relief, said skirt set back from said inner diameter of said flange to form an inner relief,
a bottom ring having an annular rim, said rim having an outer rim diameter and an inner rim diameter, an upper cuff extending upwardly from said rim adjacent said inner rim diameter, said upper cuff being annular, said upper cuff set back from said outer rim diameter to form an annular spring seat, a lower cuff extending downwardly from said rim (of said bottom ring) adjacent said inner rim diameter, said lower cuff set back from said outer rim diameter to form an annular ledge, said lower cuff including a pair of notches disposed diametrically opposite one another,
a return spring extending between upper and lower ends, said upper end configured to seat against said outer relief of said top ring, said lower end configured to seat against said spring seat of said bottom ring, and
a loose key in direct contact with and selectively moveable relative to said annular rim of said bottom ring.
15. The conversion kit of claim 14 , wherein said loose key has a first protruding end and a second protruding end, said first and second protruding ends adapted to nest within said notches of said bottom ring.
16. The conversion kit of claim 14 , wherein said loose key having an overall length greater than said diameter of said outer rim diameter.
17. The conversion kit of claim 14 , wherein said loose key has a generally rectangular cross-section.
18. The conversion kit of claim 14 , wherein said first protruding end has a major T-shaped head, said major T-shaped head having a major width.
19. The conversion kit of claim 18 , wherein said second protruding end has a minor t-shaped head, said minor t-shaped head having a minor width less than said major width.
20. A piston valve for a brass-wind musical instrument comprising:
a generally cylindrical valve body having a top end and a bottom end, said valve body having a generally constant body diameter defining a central longitudinal axis along which reciprocating actuation of said piston valve occurs, at least one transversely extending cross-port in said valve body for accommodating the passage of air passing though the brass-wind musical instrument,
a generally cylindrical spring barrel extending between a base and a neck, said base in direct abutting contact with said top end of said valve body, said spring barrel having a barrel diameter that is smaller than said body diameter of said valve body, a first keyway disposed in said spring barrel, a second keyway disposed in said spring barrel diametrically opposite said first keyway, each of said first and second keyways extending from said base axially toward respective terminal ends adjacent said neck, said first keyway having a generally constant width, said second keyway having a generally constant width, said width of said second keyway being smaller than said width of said first keyway,
a valve stem extending axially between opposite ends, a coupling at one end of said valve stem configured to connect to said neck of said spring barrel, a finger pad at the other end of said valve stem, a shaft extending axially between said coupling and said finger pad, a keeper slidably disposed on said shaft, a bumper pad disposed on said shaft between said keeper and said coupling,
a top ring captured between said coupling of said valve stem and said neck of said spring barrel, said top ring having an annular upper flange, said upper flange having an outer diameter and an inner diameter, said outer diameter of said upper flange being greater than said barrel diameter, said inner diameter being smaller than said barrel diameter, a skirt extending downwardly from said upper flange, said skirt set back from said outer diameter of said upper flange to form an outer relief, said skirt set back from said inner diameter of said flange to form an inner relief, said inner relief configured to overlie said neck of said spring barrel and be compressed by said coupling of said valve stem, said inner relief having a diameter larger than said barrel diameter,
a bottom ring slidably disposed around said spring barrel, said bottom ring having an annular rim, said rim having an outer rim diameter and an inner rim diameter, an upper cuff extending upwardly from said rim adjacent said inner rim diameter, said upper cuff being annular, said upper cuff set back from said outer rim diameter to form an annular spring seat, a lower cuff extending downwardly from said rim of said bottom ring adjacent said inner rim diameter, said lower cuff set back from said outer rim diameter to form an annular ledge, said lower cuff including a pair of notches disposed diametrically opposite one another, each said notch of said lower cuff having a width generally equal to said width of said first keyway,
a return spring disposed around said spring barrel, said return spring extending between upper and lower ends, said upper end seated against said outer relief of said top ring, said lower end seated against said spring seat of said bottom ring,
a loose key extending transversely through said first and second keyways of said spring barrel, said loose key being in direct contact with and selectively moveable relative to said annular rim of said bottom ring, said loose key having a first protruding end in registry with said first keyway and a second protruding end in registry with said second keyway, said first and second protruding ends adapted to nest within said notches of said bottom ring.