Method of manufacturing an electric lamp, and device for performing such a method
AssigneeU.S. Philips Corporation
InventorHendrik Romberg
Life of this patent
Estimating the term…
Abstract
Method of manufacturing an electric lamp having a glass tubular part (101) with a longitudinal axis, which part is sealed by a sealing member in which firstly a constriction with a collar (105) is formed by means of heating at one end of the tubular part whereafter the sealing member is secured in a gas-tight manner. The constriction in the tubular part is provided at some distance from the end whereafter in the same fixture the tubular part is divided by means of fusing at the area of the constriction and the two wall portions located on either side of the constriction are moved apart in the axial direction.
Claims17
A method of manufacturing an elongate tubular lamp vessel having a collar at each end, said method comprising:
- (a) providing a glass tube with a predetermined length;
- (b) near each end of said glass tube, circumferentially clamping said tube at two adjacent clamping positions;
- (c) heating the portions of said glass tube between each of said adjacent clamping positions to the working temperature of the glass;
- (d) forming a constriction in said heated portions of said glass tube between each of said adjacent clamping positions;
- (e) separating the end portions of the tube between the tube ends and said constriction by heating the glass tube at each constriction in a narrow circumferential region and axially pulling the end portions from the remainder of the tube, leaving a length of tube with a collar at each end.
An apparatus for manufacturing a glass tube having a collar at each end, said apparatus comprising:
- two spaced pairs of clamping means for holding a length of glass tube, the clamping means of each pair being locatable for clamping a said tube at two adjacent positions near a respective end of said length of glass tube, said clamping means being rotatable for allowing rotation of a glass tube held in said clamping means;
- a first burner locatable for heating said tube to the working temperature of the glass in the regions between the clamping means of each pair of clamping means;
- profiling means comprising profiling rollers axially locatable and laterally moveable against said glass tube in the regions between the clamping means of each pair for forming a constriction in said tube in said regions;
- a second burner locatable for severing said glass tube at the area of each constriction, each burner comprising a first opening for forming a pencil-tipped flame for heating said tube in a narrow axial region, and a pair of openings bounding said first opening for supplying a stream of cooling gas for cooling said tube in the axial regions immediately adjacent said narrow axial heated region;
- means for rotating said clamping means for rotating said tube at predetermined rotational speeds;
- and
- means for axially moving the outer clamping means of each pair away from the respective inner clamping means of each pair while said clamping means hold respective portions of a glass tube secured therein.
Dependencies are inferred from the claim text.