Electric lamp and discharge devices – With envelope – Having base and connector
Reexamination Certificate
1998-11-06
2001-04-10
Patel, Nimeshkumar D. (Department: 2879)
Electric lamp and discharge devices
With envelope
Having base and connector
C313S318010, C313S318090, C313S318100
Reexamination Certificate
active
06215236
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates generally to a lamp in which a lamp capsule and a retaining plate are connected with each other by allowing the retaining plate to chuck the lamp at the pinch-sealed portion, particularly to a technique of preventing breakage and backlash of the lamp capsule.
DESCRIPTION OF THE RELATED ART
Lamps, for example, H4 type halogen lamps which are employed most widely, are each of the structure, in which the lamp capsule thereof has a glass bulb which is closed at one end with a pinch-sealed portion and at the other end with an evacuating portion, and filaments are extended respectively across suitable ones of a plurality of leads penetrating the pinch-sealed portion and being retained by that portion.
FIG. 5
shows schematically an example of the lamp capsule a of the conventional halogen lamp as described above. In the lamp capsule a, a substantially flat pinch-sealed portion b has on each crosswise side face a pair of ridges c (only one ridge is shown), and a pair of engaging protrusions d formed substantially at the center of each side face. The lamp capsule a is chucked at the pinch-sealed portion b by a metal retaining plate e which is to be set in a base not shown.
Two pairs of opposing intermediate holding pieces f (only one pair is shown) and two pairs of opposing side holding pieces g (only one pair is shown) are formed on the retaining plate e.
Thus, when the lamp capsule a is inserted at the pinch-sealed portion b down into the retaining plate e, the portion b is chucked between the two pairs of opposing intermediate holding pieces f and between the two pairs of side holding pieces g. In this instance, the intermediate holding pieces f are brought into resilient contact with the respective side faces at the middle part of the pinch-sealed portion b and are also engaged with the upper faces of the engaging protrusions d formed on the side faces of the pinch-sealed portion b, while the side holding pieces g are brought into resilient contact with the respective side faces at the middle part of the pinch-sealed portion b and are also engaged with that end i of the glass bulb h of the lamp capsule a which is located on the pinch-sealed portion side. The engagements achieved by these holding pieces prevent the lamp capsule a from slipping off from the retaining plate e.
However, in such a lamp as described above, poor processing accuracy in the lamp capsule a, particularly at the pinch-sealed portion b, forms gaps between the end i of the glass bulb h and the tips of the respective side holding pieces g of the retaining plate e holding the lamp capsule a to cause backlash of the lamp capsule a with respect to the retaining plate e, disadvantageously.
Such backlash of the lamp capsule a causes displacement of the filaments whose positions should strictly be restricted to disturb the light distribution pattern of lighting fixtures.
The lamp capsule a involves a problem due to its structure in which the tip of each sharp-edged side holding piece g of the retaining plate e is brought into contact with the end i of the glass bulb h to cause damages so-called kinking or cracking in the glass bulb h and the pinch-sealed portion b, resulting in the occurrence of many defectives in the process of producing lamp capsules a.
SUMMARY OF THE INVENTION
In view of the problems described above, the lamp according to the present invention is directed to prevent breakage and backlash of lamp capsules.
In the lamp according to the present invention, with a view to solving the problems described above, a plurality of holding pieces are formed on a retaining plate so as to chuck the lamp capsule at the pinch-sealed portion, and thick-wall portions are formed on the glass bulb-side end of the pinch-sealed portion except for the widthwise central part, so that the thick-wall portions may be brought into contact with the holding pieces.
Accordingly, backlash of the lamp capsule can be prevented by the thick-wall portions, and since the thick-wall portions are formed except for the widthwise central part of the pinch-sealed portion by urging the glass at the central part toward the thick-wall portions when the pinch-sealed portion is molded, the thick-wall portions can be molded in a stable form.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings illustrated by way of examples the principles of the invention.
REFERENCES:
patent: 4139794 (1979-02-01), Malm et al.
patent: 4883434 (1989-11-01), Toyoshima
patent: 5339002 (1994-08-01), Braun et al.
patent: 5818154 (1998-10-01), Helbig et al.
patent: 5994825 (1999-11-01), Goto et al.
Gotoh Hiroshi
Umehara Masayuki
Guharay Karabi
Koito Manufacturing Co. Ltd.
Patel Nimeshkumar D.
Sughrue Mion Zinn Macpeak & Seas, PLLC
LandOfFree
Halogen lamp having thick wall pinch seal portion does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Halogen lamp having thick wall pinch seal portion, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Halogen lamp having thick wall pinch seal portion will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2534445