US3617787A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bimetallic spring support for a shadow mask
Assignee: Individual
•
Filing: 1969-06-19
•
Granted: 1971-11-02
•
Expires: 1989-06-19
Abstract
Abstract In order to check displacement of a shadow mask in a plane at right-angles to the axis of a cathode-ray tube, it is suspended from three flat springs consisting of two strips which are welded together along their narrow sides and constitute a bimetal; the coefficient of expansion of said springs is adapted to the location of the springs on the shadow mask edge by the location of the supporting point of the spring to the envelope, on a line at right-angles to the welding seam at different distances from the welding seam.
Inventors
- 👤 Gerardus Wilhelmus Plukker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 19:18
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/06; H01J29/07; H01J29/073; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12771; Y10T428/12861; Y10T428/12951; Y10T428/12958; Y10T428/12965
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
249 words
A cathode ray tube comprising an evacuated envelope having a longitudinal axis and a substantially rectangular window portion at one end thereof intersecting said axis at right-angles, a plurality of phosphor triads constituting a luminescent screen disposed on said window, a substantIally rectangular shadow mask having apertures therein aligned with said phosphor triads, and at least three strip-shaped flat springs positioned along the sides of the mask for supporting said shadow mask, each of said springs comprising two strips each of a different metal and each having a given longitudinal axis, said strips being joined along an edge extending in a direction parallel to the longitudinal axis of each strip, one end of said spring being secured to said mask and the other end being supported by an upright edge of the window by means of a support with the flat sides of said strips being parallel to the upright sides of the mask, said support being positioned on a line at right-angles to the joined edge at a distance therefrom at which the expansion of a free portion of the spring between the end of the spring secured to the mask and said support is substantially equal to the expansion of a portion of the mask located between the end of the spring secured to the mask and the center of the side of the mask whereby upon heating, substantially no displacement of the mask occurs in a plane at right-angles to the longitudinal axis of the tube.
Claim 2
Dependent Claim
249 words
A cathode ray tube comprising an evacuated envelope having a longitudinal axis and a substantially rectangular window portion at one end thereof intersecting said axis at right-angles, a plurality of phosphor triads constituting a luminescent screen disposed on said window, a substantIally rectangular shadow mask having apertures therein aligned with said phosphor triads, and at least three strip-shaped flat springs positioned along the sides of the mask for supporting said shadow mask, each of said springs comprising two strips each of a different metal and each having a given longitudinal axis, said strips being joined along an edge extending in a direction parallel to the longitudinal axis of each strip, one end of said spring being secured to said mask and the other end being supported by an upright edge of the window by means of a support with the flat sides of said strips being parallel to the upright sides of the mask, said support being positioned on a line at right-angles to the joined edge at a distance therefrom at which the expansion of a free portion of the spring between the end of the spring secured to the mask and said support is substantially equal to the expansion of a portion of the mask located between the end of the spring secured to the mask and the center of the side of the mask whereby upon heating, substantially no displacement of the mask occurs in a plane at right-angles to the longitudinal axis of the tube.
Claim 3
Dependent Claim
123 words
A color television picture tube as claimed in claim 1, wherein a supporting spring is secured to a side of the mask in such manner that said support is situated opposite to the center of said side and on the joined edge of the bimetallic strip of the supporting spring, two other supporting springs being secured symmetrically with respect to the axis extending through said center and each being in the center of one of the sides extending parallel to said axis, the free ends pointing in the direction of the fourth straight side and said support of the said springs being situated each on the extreme edge of the part having the smallest coefficient of thermal expansion of the associated bimetallic spring.
Claim 4
Dependent Claim
26 words
A color television picture tube as claimed in claim 2 wherein said support is a lug provided at the free end of the flat supporting spring.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-01 | 1975-05-03 | 1975-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-01 | 1979-05-03 | 1979-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-01 | 1983-05-03 | 1983-11-02 | $7700.00 | Window Closed / Lapsed |