Low-pressure sodium discharge lamp
First Claim
1. A low-pressure sodium discharge lamp provided withan evacuated, tubular glass outer bulb which is closed in a gastight mannerwith a first end potion where a glass stemtube enters the outer bulb, having a pinch seal inside the outer bulb, which end portion supports a lamp cap provided with contacts, andwith a second end portion having a dome shape;
- a glass discharge tube bent into a U-shape with end portions which are each closed in a gastight manner and each have a pinch through which a respective current conductor is passed to an electrode arranged in the end portion in question, which discharge tube is filled with sodium and rare gas;
electrical conductors which extend each from a respective contact of the lamp cap through the pinch seal so as to be connected to a respective current conductor;
a substantially plane mica plate with openings through each of which a respective pinch is passed, acting as a first centring member which keeps the discharge tube centred in the outer bulb, and a second centring member for the discharge tube in the second end portion of the outer bulb,characterized in that the mica plate has projecting teeth at its periphery which are bent towards the lamp cap and bear on the outer bulb with clamping action.
1 Assignment
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Accused Products
Abstract
The low pressure sodium discharge lamp has an outer envelope (1) in which a U-shaped discharge tube (10) is accommodated. A mica disk (20) having holes (21 ) through which pinches (11) of the discharge tube extend, keeps the discharge tube centered. The mica disk (20) has teeth (22) at its periphery, which are bent towards the lamp base (5) and clampingly engage the outer envelope. The disk allows for the outer envelope to be fused to a flared tube (3) in a drop-seal process and provides several additional features.
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Citations
20 Claims
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1. A low-pressure sodium discharge lamp provided with
an evacuated, tubular glass outer bulb which is closed in a gastight manner with a first end potion where a glass stemtube enters the outer bulb, having a pinch seal inside the outer bulb, which end portion supports a lamp cap provided with contacts, and with a second end portion having a dome shape; -
a glass discharge tube bent into a U-shape with end portions which are each closed in a gastight manner and each have a pinch through which a respective current conductor is passed to an electrode arranged in the end portion in question, which discharge tube is filled with sodium and rare gas; electrical conductors which extend each from a respective contact of the lamp cap through the pinch seal so as to be connected to a respective current conductor; a substantially plane mica plate with openings through each of which a respective pinch is passed, acting as a first centring member which keeps the discharge tube centred in the outer bulb, and a second centring member for the discharge tube in the second end portion of the outer bulb, characterized in that the mica plate has projecting teeth at its periphery which are bent towards the lamp cap and bear on the outer bulb with clamping action. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification