A gas discharge tube lighting source includes electrodes and a gas (typically comprising a noble gas) within a glass envelope. Lighting sources that include gas discharge tubes include fluorescent, compact fluorescent, mercury, sodium, and high intensity discharge lamps. These lighting sources rely on an electric discharge between the electrodes to ionize the gas to create illumination.
A compact fluorescent lamp (CFL) is a fluorescent lamp typically shaped to replace an incandescent lamp using the same lamp socket as the incandescent lamp. An integrated CFL includes an electronic ballast in the base of the CFL to generate sufficient voltage to support arcing between the electrodes within the discharge tube; otherwise a ballast needs to be installed in the lighting fixture.
Conventionally, the gas-tight seal of the discharge tube is accomplished by inserting a stem assembly into the open ends of the discharge tube. The stem assembly can include lead-in wires, an exhaust tube, and in some configurations a coil attached to the lead-in wires. The stem assembly can include a flare which has an outer diameter along its entire length that fits within the inner diameter of the discharge tube. The stem assembly is inserted into the discharge tube and positioned at a predetermined location. The seal between the discharge tube inner surface and the outer surface of the stem flare is secured using thermal bonding. The discharge tube edge and the stem flare can be heated in the range of about 800-1000° C. By heating the glass discharge tube and the glass stem flare the two parts join together.
Devices and methods in accordance with embodiments provide a mechanical connection between a discharge tube and a collar. This mechanical connection is achieved without the use of adhesives. In accordance with embodiments, the collar clamps to a seal ring of the discharge tube.
Tube portion 210 has a first portion that has a diameter Dstem that is sized to be less than the discharge tube inner diameter. Flare 220 increases the diameter of tube portion 210 from the diameter Dstem to a diameter Dring which is greater than the outer diameter of the discharge tube end.
Each of section 410A, 410B includes arm 420A, 420B which each include pawl 424 (i.e., 424A and 424B) projecting from a distal end of the arm. At a corresponding position on the other section is located frame 428A, 428B. Respective corresponding arms can be inserted through respective corresponding frames to join sections 410A, 410B around the assembled discharge tube to form discharge tube collar 400. Once the arm is inserted into the frames so that pawl passes through the frame, the pawl secures the arm from withdrawing. In accordance with some embodiments, a tab can be formed inside the frame or on the arm. Depressing the tab can force the arm into a position that releases the pawl from contact with the frame.
In some implementations, a surface of the frame can have teeth that engage the pawl to form a ratchet. In such implementations, the pawl need not be inserted through the frame to secure the two sections of the discharge tube collar together.
In accordance with embodiments, discharge tube collar 400 includes lower clamp 430 and upper clamp 440. Each clamp is formed from clamping members located on both sections 410A, 410B. Lower clamp 430 extends from base 450 of the discharge tube collar. In some implementations, lower clamp 430 can have a cross section that complements the cross section of the discharge tube to create an improved fit when clamped together. For example, in some implementations the lower clamp can have an arcuate cross section with a radius that about matches the circumference of the discharge tube. In other implementations, the radius of the lower clamp cross section can be the long axis of an oval, where the short axis of the oval corresponds to about the circumference of the discharge tube. In this implementation, aperture 470 is about a geometric oval in shape. The geometric oval shape can reduce deformation of, and stress against, the discharge tube due to manufacturing tolerances of the discharge tube. Upper clamp 440 extends from base 450 of the discharge tube collar and includes projection 444 at an end distal from the base.
Flexible clamp 460 extends from sidewall 414 of discharge tube collar 400. One end of flexible clamp is in connection with a discharge tube collar section. At an end distal from the connection, flexible clamp 460 is free from the discharge tube collar section. Flexible clamp 464 extends from base 450 at a position opposing the position of flexible clamp 460. Flexible clamp 460, 464 act as springs to apply pressure against a discharge tube when assembled into the discharge tube collar. The pressure is exerted against the discharge tube to position each leg of the discharge tube within a respective aperture 470. Either section 410A, section 410B, or both sections 410A, 410B can include flexible clamps 460, 464.
In accordance with embodiments, components of the finished lamp assembly can be combined in an adhesive-less manner—i.e., adhesive-less having the meaning of without any glue, thermal bonding, and/or adhesive.
Although specific hardware and methods have been described herein, note that any number of other configurations may be provided in accordance with embodiments of the invention. Thus, while there have been shown, described, and pointed out fundamental novel features of the invention, it will be understood that various omissions, substitutions, and changes in the form and details of the illustrated embodiments, and in their operation, may be made by those skilled in the art without departing from the spirit and scope of the invention. Substitutions of elements from one embodiment to another are also fully intended and contemplated. The invention is defined solely with regard to the claims appended hereto, and equivalents of the recitations therein.
This patent application claims the benefit of priority, under 35 U.S.C. §119, of U.S. Provisional Patent Application Ser. No. 62/060,961, filed Oct. 7, 2014, titled “ADHESIVELESS ASSEMBLY FOR ELECTRONIC COMPACT FLUORESCENT LAMPS” the entire disclosure of which is incorporated herein by reference.
Number | Date | Country | |
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62060961 | Oct 2014 | US |