Single-ended electric discharge lamp having tubular envelope with partition means that provides a helical arc path

Claim 2

A compact single-ended fluorescent lamp adapted for operation at a power input loading of from 25 to 100 watts per foot of lamp length, said lamp comprising the combination of; a sealed vitreous envelope of tubular configuration and substantially uniform circular cross-section that contains an ionizable medium, a coaxially disposed hollow vitreous tube joined to one end of said envelope and extending therefrom toward the opposite end of the envelope, said tube being of substantially uniform circular cross-section and shorter than said envelope so that the free end of the tube is spaced from the proximate end wall of the envelope, means defining a single helical discharge channel within said envelope comprising an electrically non-conductive planar partition of helical configuration that is integral with and spirals around said hollow tube at a predetermined uniform pitch and extends laterally therefrom to the walls of said envelope, a pair of spaced electrodes disposed within said envelope at loCations such that the arc path begins at one of said electrodes, traverses the single helical channel, and then terminates at the other of said electrodes, conductor means sealed through said envelope and connectingn the respective electrodes to a plurality of exterior contact elements located on a base member that is secured to said envelope, and a layer of ultraviolet-responsive phosphor on the surfaces of said helical partition, the pitch of said helical partition and the diameter of said hollow tube relative to that of said tubular envelope being such that said helical discharge channel is substantially rectangular in cross-section and elongated in a direction parallel to the envelope axis.

Claim 3

The compact single-ended fluorescent lamp of claim 1 wherein; said helical partition has a pitch of from about one to two turns per inch, and the diameter of said envelope is approximately twice that of the hollow tube.

Claim 4

The compact single-ended fluorescent lamp of claim 1 wherein the pitch of the helical partition and the diameters of said envelope and hollow tube are so correlated that ratio of the length dimension to the width dimension of the substantially rectangular cross-section of said helical discharge channel is approximately 2:1.

Claim 5

The compact single-ended fluorescent lamp of claim 1 wherein; said helical parition comprises a ribbon of sheet metal that is coated with a layer of insulating material, and a layer of ultraviolet-responsive phosphor is also disposed on the interior surface of the hollow tube that constitutes part of said helical discharge channel.

Claim 6

The compact single-ended fluorescent lamp of claim 4 wherein; said layer of insulating material comprises a coating of fused glass, and said envelope is composed of glass and is devoid of phosphor.

Claim 7

A compact single-ended fluorescent lamp adapted for operation at a power input loading of from 25 to 100 watts per foot of lamp length, said lamp comprising the combination of; a vitreous envelope of cylindrical configuration that has a sealed end portion and contains a predetermined amount of mercury and a fill gas at a pressure below 10 torr, a hollow vitreous tube of cylindrical configuration joined to one end of said envelope and extending therefrom toward the opposite end of the envelope, said tube being coaxially disposed within and shorter than said envelope so that the free end of the tube is spaced from the proximate end wall of the envelope. means defining a single helical discharge channel within said envelope comprising an electrically non-conductive planar partition of helical configuration that is integral with and spirals around said hollow tube at a predetermined uniform pitch and extends laterally therefrom to the walls of said envelope, a pair of spaced thermionic electrodes disposed within said envelope at locations such that the arc path begins at one of said electrodes, traverses the single helical channel, and then terminates at the other of said electrodes, a base assembly that is secured to the sealed end portion of said envelope and includes a plurality of exposed contact elements, and a layer of ultraviolet-responsive phosphor on the surfaces of said helical partition, one of said electrodes being located at the sealed end of the envelope in the space between said hollow tube and the proximate side wall of said envelope and connected directly to at least one of said exposed contact elements by a conductor that extends through the sealed end of said envelope, the other of said electrodes being (a) located at the opposite end of the envelope in the space between the free end of said hollow tube and proximate end wall of the envelope and (b) held in such position by a rigid conductor that extends through the hollow tube and the sealed end of the envelope and is connected to another of said exposed contact elements so that the helical arc path is devoid of conductors and eXtends from one electrode and spirals around the tube directly to the other electrode at the opposite end of the lamp, and the pitch of said helical partition and the diameter of said hollow cylindrical tube relative to that of said cylindrical envelope being such that the cross-sectional configuration of the helical discharge channel is substantially rectangular and elongated in a direction parallel to the envelope axis.

Claim 8

A compact single-ended fluorescent lamp adapted for operation at a power input loading of from 25 to 100 watts per foot of lamp length, said lamp comprising the combination of; a vitreous envelope of cylindrical configuration that has a sealed end portion and contains a predetermined amount of mercury and a fill gas at a pressure below 10 torr, a hollow vitreous tube of cylindrical configuration joined to one end of said envelope and extending therefrom toward the opposite end of the envelope, said tube being coaxially disposed within and shorter than said envelope so that the free end of the tube is spaced from the proximate end wall of the envelope. means defining a single helical discharge channel within said envelope comprising an electrically non-conductive planar partition of helical configuration that is integral with and spirals around said hollow tube at a predetermined uniform pitch and extends laterally therefrom to the walls of said envelope, a pair of spaced thermionic electrodes disposed within said envelope at locations such that the arc path begins at one of said electrodes, traverses the single helical channel, and then terminates at the other of said electrodes, a base assembly that is secured to the sealed end portion of said envelope and includes a plurality of exposed contact elements, and a layer of ultraviolet-responsive phosphor on the surfaces of said helical partition, one of said electrodes being located at the sealed end of the envelope in the space between said hollow tube and the proximate side wall of said envelope and connected directly to at least one of said exposed contact elements by a conductor that extends through the sealed end of said envelope, the other of said electrodes being (a) located at the opposite end of the envelope in the space between the free end of said hollow tube and proximate end wall of the envelope and (b) held in such position by a rigid conductor that extends through the hollow tube and the sealed end of the envelope and is connected to another of said exposed contact elements so that the helical arc path is devoid of conductors and eXtends from one electrode and spirals around the tube directly to the other electrode at the opposite end of the lamp, and the pitch of said helical partition and the diameter of said hollow cylindrical tube relative to that of said cylindrical envelope being such that the cross-sectional configuration of the helical discharge channel is substantially rectangular and elongated in a direction parallel to the envelope axis.

Claim 9

The single-ended fluorescent lamp of claim 6 wherein said base assembly includes two pairs of exposed contact elements and the ends of each of said electrodes are connected to a different pair of said contact elements by a pair of associated conductors.

Claim 10

The single-ended fluorescent lamp of claim 6 wherein; said lamp is of the self-starting type and includes and integral starting resistor, and said resistor is located within and inclosed by said hollow tube.

Claim 11

The self-starting single-ended fluorescent lamp of claim 8 wherein, said base assembly includes a single pair of exposed contact elements, one of said electrodes is located adjacent the free end of said hollow tube and connected to an adjacent auxiliary electrode in series therewith, the other of said electrodes is located at the opposite end of said envelope and connected to a second adjacent auxiliary electrode in series therewith, and said conductors connect the respective electrode-auxiliary electrode pairs and said starting resistor in series with each other and said pair of exposed contact elements.

Claim 12

The self-starting single-ended fluorescent lamp of claim 9, wherein; the free end of said hollow tube is sealed off, said resistor extends along and is spaced from the hollow tube, and a layer of ultra-violet-responsive phosphor is also disposed on the interior surface of said hollow tube that constitutes part of the helical discharge channel.