JPH0359548B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to discharge lamps, and more particularly to a type of fluorescent lamp having a relatively long discharge tube bent into a coiled configuration to make it more compact.

U-shaped or generally circularly bent fluorescent lamps are known, and more recently smaller tubes with such shapes have been manufactured as a potential replacement for general lighting service (GLS) lamps. Taking this further, the discharge tube was first bent at the center by 180° with respect to one axis.
At one-quarter and three-quarters of the length, bends are made by 180° with respect to the orthogonal axes. More recently, with the development of fluorescent lamp emitters that can withstand much higher power loads, the tubes have been reduced sufficiently to allow the tubes to be bent to a volume approaching that of filament lamps for general lighting. It became possible to reduce the diameter. An example of such a lamp is British Patent No.
Disclosed in No. 2033653A.

However, the lamp suffers from the disadvantage that, from a handling safety point of view, it must be enclosed within a protective outer bulb, which results in a loss of light and a temperature rise due to heat generated within the ballast. In order to avoid this, it is necessary to use complex means to regulate the mercury vapor pressure within the fluorescent tube to the desired level. Another drawback is that conventional lamps such as those described above cannot be used in relatively flat lighting fixtures.

Another example of a coiled discharge tube is disclosed in British Patent No. 1582885, in which:
A tube is used that is spirally bent in opposite directions from the center toward both ends. The spiral extends such that the ends face each other in the same direction and are above the center. However, this configuration has the disadvantage that it cannot be used with a substantially flat fixture, and may be considered somewhat cumbersome to handle. Also, manufacturing tubes of this shape carries the risk of insufficient adhesion of the phosphor coating, which also results in some loss of light output and reduces the light output over the life of the lamp. It is thought that this will have a negative impact on maintenance.

The circular tube described above also suffers from the above-mentioned drawbacks, and is considered to be relatively inefficient in terms of space usage.

The U-shaped tube mentioned above is also considered to be relatively inefficient in terms of space usage, unless long and narrow fittings are used.

The object is to provide a discharge lamp with a bent or coiled discharge tube in order to achieve a very compact lamp that does not require protection by an outer bulb or an outer frame.

According to the invention, the shape is such that it is arranged substantially in one plane and defines a substantial part of the boundary of said one area, with both ends re-entered within said area and said A fluorescent tube is provided, the portion defining the boundary including at least one straight portion.

Further, according to the present invention, the shape has three straight parts arranged substantially in one plane and located along three sides of a rectangle, and the end part is bent and the above-mentioned a discharge tube re-entered within the rectangle at a fourth side thereof, and a discharge tube located within the housing in or near the plane to receive the end of the tube and provide electrical power to the tube and at least one support arm extending from the lamp support housing and attached to the tube at a central one of the three sides. Ru.

Still further in accordance with the invention, the folded portions are folded to form a plurality of portions, at least some of which portions are straight to form a substantially planar region; A support housing is re-entered within the region and adapted to receive and support the ends, the housing having means for rigidly supporting the tube between the ends. A fluorescent lamp is provided.

The invention will now be explained in more detail with reference to the embodiments shown in the drawings.

The discharge tube of the lamp according to the invention defines a boundary for an area in a plane, the boundary having many different shapes.
The tube also has a straight section where the tube is not softened and there is less risk of disturbing the luminous material applied to the inner wall of the tube. Advantageously, said boundary is polygonal. However, in the embodiment of the present invention, the shape of this boundary is substantially square. It is preferable that both ends of the tube are also straight.
They are allowed to reenter the area.

A lamp according to this embodiment of the invention is shown in bottom and elevation views in FIGS. 1 and 2, respectively. As shown, the discharge tube 1 has 2,
It is bent by 90 degrees at 2' to form three sides of a quadrilateral (square in this embodiment) and is otherwise similar to a conventional fluorescent tube. Tube 1 now at 3 and 3'
It is bent further by 180° and the end 4 is re-entered into the square thus formed.
The tube defines the boundary of a square area, ignoring the boundary interruption required by the re-entry end. All bends are made about parallel axes such that the tube shape is oblate, ie, the tube lies in a plane with a thickness substantially equal to its diameter.

Inside the square formed by the bent tube, a lamp support housing 5 is arranged in this embodiment, into which the end 4 of the discharge tube 1 is mounted. The housing 5 confines the starting part and the electrical connections and is formed as two parts 5a and 5b that are crimped together to facilitate assembly. In this embodiment, part 5a is the part in which the starting parts and electrical connections are mounted, and part 5b is formed as a simple cover. The housing is formed in this embodiment with two arms 6, each of which terminates in a circular support gripping the central part 7 of the tube 1. The arms also form two parts, each of which includes a housing 5.
one of the parts of its housing 5 so as to enclose the tube when the parts are crimped together;
is related to.

Further, as shown in FIGS. 1 and 2, the upper portion 5a of the housing 5 is provided with a recess 8 for accommodating a lamp holder.
Two terminal pins 9 are provided in the recess. The recess 8 and the terminal pin 9 can take any suitable form as required.

The illustrated arrangement in which the housing 5 has two arms gripping the central portion 7 of the tube 1 provides effective support to the tube 1 to prevent relative movement of the discharge tube and housing during handling. Such an arrangement is particularly advantageous, as it provides a convenient and therefore natural point from which to grip the lamp, reducing the risk of tampering with the tube itself. The arrangement is also advantageous in that it does not require excessive precision when assembling the ends of the tube. Thus, in applications where the tube support and tube are held together by other means, such as adhesives, no or less support may be provided. The arms may also be in other positions. For example, 1 for each of the 3 straight parts of the tube.
Two support arms could be provided, but in that case the ease of assembly would be reduced.

Figure 3 shows that the two parts of the housing 5 are connected to the arm 6.
FIG. 2 is a side elevational view of the lamp whose main feature is the manner in which the tube 1 is gripped.

FIG. 4 is a plan view of the lamp from the opposite side to FIG. 1, with cover portion 5b removed and showing the parts installed within housing 5. FIG.

FIG. 4 shows electrical wiring, and in this embodiment a printed circuit board 10 is used for the wiring.
is provided, and components such as a known glow switch 11 and a radio interference suppression capacitor 12 are attached thereto as required. This printed circuit board may be replaced by other means of making electrical connections, and the lamp of the invention may be satisfactorily provided without the capacitor 12 or with the starting switch and capacitor located outside the lamp. It can work. Although the contents of the housing 5 may be varied as desired within the scope of the invention, it is advantageous to include an electronic ballast. Similarly, depending on the circuit used in the lamp, other pins may be provided in addition to the two terminal pins described above.

The lamp exhaust tube, indicated at 13, between the electrical connections to the tube electrodes is made substantially longer than is normally found in discharge tubes of this type. This long vent provides a cool area for condensing the reservoir of liquid mercury, whose temperature determines the mercury vapor pressure and must be able to partially evaporate and be usable during the life of the lamp. . The length of the outlet is selected to ensure approximately optimal performance of the lamp. According to the invention, a long exhaust port can be advantageously used, which has various advantages, and in this embodiment the exhaust port is housed within the housing 5. The exhaust tube in the illustrated embodiment is tipped off with a solid glass tipoff 4, with condensed mercury droplets located at 15 after the lamp has been operated for a sufficient period of time. Although such long exhaust ports may be provided at each end of the discharge tube, such a configuration is not preferred.

Known mercury amalgam systems may be used for vapor pressure control, but this adds further complexity.

In this embodiment, a conventional getter/mercury dispenser ring, such as the one shown at 16, is preferably used to introduce a controlled small amount of mercury. This ring, shown in more detail in the perspective view of Figure 4a, consists of a nickel-plated iron container containing a mixture of "ST101" (Zr/Al getter) and a mercury/titanium alloy. It is. The above-mentioned low amounts of mercury introduced as vapor are particularly advantageous for compact household lamps. For example, the risk of loss of the luminescent body at the bend due to rolling mercury droplets is reduced and the lamp stabilizes more quickly. Also, the amount of mercury released into the environment will be reduced, which is particularly important when the lamp is used for domestic purposes.

In the lamps of the embodiments shown in Figures 1 to 4, the charged gas is within the range of 2 to 7 torr (5 torr
Preferred is argon (considered most suitable). The amount of mercury applied is within the range of 1 to 7 mg.

Various measures are recommended to promote cooling. Preferably, the tube cathode is outside the housing 5, as indicated at 17. The shape of the housing 5 with arms 6 as shown, along with cutouts such as those shown in FIG. 1, facilitate ventilation and cooling. However, the primary purpose of the notch in the housing 5 is to provide elasticity for gripping and supporting the end 4 of the tube 1, and the purpose of the notch in the arm 6 is to provide a mechanism for locking the two parts of the housing together. It is to form a part of.

As a method for shaping the tube 1 according to the invention, a straight tube (FIG. 5a) coated inside with a suitable luminous material in a conventional manner is used.
, heat the tube near its ends, bend the tube by 180° at those points (Figure 5b), and repeat the process to bend the tube by 90° at the 1/3 point. A method of bending it (FIG. 5c) is used. As shown, the bend in the tube is relatively sharp, but of course this is limited to practical limits. During bending, it is desirable to appropriately pressurize the tube with an inert gas to prevent the softened tube from collapsing at the bend.

The tube may be formed of soda lime glass, as fluorescent lamp tubes are commonly used, or any other material suitable for making discharge tubes. 1st to 4th
In the embodiment shown, the tube has a diameter of
Preferably, the diameter is 12.75 to 13.25 mm (outer diameter) and the wall thickness is 0.8 to 0.9 mm. The preferred centerline length after bending is 500-520mm, and the spacing between the cathodes is approximately 450mm.
~470 mm, and for such a length the lamp defines a square with sides of approximately 135 mm and no more than 141 mm.

Although Figures 1-4 illustrate one suitable embodiment, the present invention encompasses many other tube configurations that may be placed around the support housing. The sides of the area defined by the tubes need not be parallel, nor do all sides need to have straight portions. Furthermore, the invention encompasses a number of tube geometries in which the portion of the tube defining the boundary of said region as distinct from said end portion includes at least one straight portion that is not subjected to bending stress. It is something to do.

However, the embodiments shown in FIGS. 1-4 are particularly preferred.

In all embodiments of the invention, deviations of the coiled tube from the plane in which it is generally located are contemplated, as long as it is not excessive. It is not contemplated that such a deviation would be substantially larger than the tube diameter or the advantages of a generally flat lamp would be lost. However, the support housing may be at least partially out of the plane of the tube, in which case the end of the tube may be offset from the general plane sufficiently to enter the support housing. Such an arrangement is shown in side and end views in Figures 6a and 6b, respectively. Although such an arrangement is not preferred, it has the advantage of reducing the occlusion of the support housing 5 from the light on the paths leading to the sides and bottom of the lamp. The arm 6 can be repositioned as shown at 19 to accommodate the displaced support housing.

Other small deviations may be tolerated, for example for aesthetic or manufacturing reasons.

The present invention is particularly useful in the field of lamps having dimensions close to common illumination filament lamps, but also in the field of lamps having dimensions comparable to, for example, known 26 mm and 38 mm diameter tubes, as well as various larger or smaller lamps. The same applies to lamps of different sizes. It can be seen that in the case of such tubes, not only the dimensions differ from those shown for the embodiments of Figures 1-4, but also other values such as fill gas pressure and mercury dosage generally differ. Will.

The lamp according to the invention can be used, for example, in place of circular lamps or U-shaped lamp combinations, which are advantageous in terms of efficiency and cost. For these purposes, the lamp of the invention may have the shape of the embodiment shown in FIGS. 1-4 and have an end cap or alternatively some type of end housing suitable for any fitting. may be used as a tube without necessarily having the central support housing in the preferred embodiment described above. An example of such a tube according to the invention is shown in FIG. 7, but the one shown does not have an end cap. It will therefore be appreciated that the present invention also encompasses a fluorescent tube shaped as described above, with or without a housing, mount, ballast or support housing. Probably.

A tube having a shape as described above, whether or not fitted with a central support housing, at least has a shape that is convenient and practical for bending the tube, and is also advantageous in terms of central support. It is considered to be advantageous in that respect. Although it is preferred that at least one third of the length of the tube is straight, the invention is not so limited.

The lamp according to the invention has the important feature that it is flat, so that it can be used in a substantially flat and unobtrusive fixture. In the case of domestic lighting fixtures, the flatness and compactness of the lamp of the present invention will provide new design space for the fixture designer.

It will be appreciated that the tube of the present invention has particular versatility as a coiled discharge tube.

[Brief explanation of drawings]

FIG. 1 is a bottom view showing a lamp according to an embodiment of the present invention, FIG. 2 is an end view of the lamp in FIG. 1, and FIG.
Figure 4 is a side view of the lamp of Figure 1; Figure 4 is a top view of the lamp of Figure 1; Figure 4 is a support housing cover with the cover removed to show the components mounted within; Top view of the lamp of Figure 1, No. 4a
The figures show further details of the getter/mercury dispenser ring in figure 4, figures 5a and 5b.
and Figures 5c and 6c illustrate the step of forming a tube into the shape according to the embodiment shown in Figure 1 of the present invention.
Figures a and 6b are side and end views, respectively, of another embodiment of the invention in which the central support housing is located outside the main plane of the lamp; Figure 7 is a side view and an end view, respectively;
FIG. 4 shows a discharge tube having a shape according to the embodiment shown in FIGS.

Claims (1)

[Claims] 1. The inside is coated with a phosphor, and substantially 1.
A discharge tube 1 arranged in two planes and bent so as to define three sides of the boundary of a rectangular area in said plane, the end 4 re-entering said rectangular area. a lamp support housing 5 substantially centrally within said rectangular area and spaced apart from said tube; and extending between said lamp support housing and said tube, said lamp support housing 5 extending between said lamp support housing and said tube; at least one support arm 6 providing substantially rigid support for said tube for positioning with respect to said lamp support housing adapted to receive and support the re-entry end of said tube. A fluorescent lamp characterized in that it is equipped with means made by the above. 2. The lamp support housing comprises two housing halves 5a, 5b, which are crimped together and locked together as a single housing. The fluorescent lamp according to item 1. 3. Each of said housing halves 5a, 5b supports said at least one support arm 6a, 6b.
3. A fluorescent lamp according to claim 2, further comprising resilient means for locking each complementary portion of the arm and the complementary portion of the arm together. 4. The fluorescent lamp according to any one of claims 1 to 3, wherein said at least one support arm is two said arms. 5. Fluorescent lamp according to claims 1 to 4, wherein at least one end 4 of the tube has a long exhaust port 13 for controlling mercury vapor pressure. 6 the lamp support housing is in an external recess 8;
6. A fluorescent lamp according to any one of claims 1 to 5, comprising: a recess; and an electrical terminal in the recess. 7. A fluorescent lamp according to claim 6, characterized in that the electrical terminals comprise terminal pins 9 arranged to connect in a direction generally perpendicular to the plane.