JPH0336032Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a tubular incandescent light bulb with improved terminal caps provided at both ends of the tubular glass bulb.

[Technical background of the invention and its problems]

having a crush seal at both ends of the glass bulb;
For example, tube-shaped light bulbs such as halogen-containing incandescent light bulbs are used in copiers and the like. The above-mentioned tube-shaped light bulb has terminal caps fixed to the end faces of the crushed seal parts at both ends thereof with an inorganic adhesive, and the above-mentioned terminal caps are made of an insulating material such as ceramic, whose vertical cross-sectional view is shown in Fig. 5, on the metal terminals. It was crowned with a mantle made of material. The outer tube 1 has two fixing grooves 2 formed so as to span the crushed sealing part of the incandescent light bulb at the right end as viewed from FIG. 5, and the terminal cap is fixed to the other end. and four kerfs 3 formed to prevent the bulb from rotating relative to the socket.
Further, an uneven groove 4 continuous in the axial direction was provided on the inner surface thereof. Figure 6 shows a fixing groove 2 that extends the outer tube 1 over the crushing sealing part of the light bulb.
It is a rear view seen from a certain side, and the above-mentioned uneven groove 4
A configuration in which a is formed is shown. The cut grooves in the outer tube were necessary to regulate the direction of light emitted by the light bulb to maintain a predetermined light distribution, and the fixing grooves were necessary to fix the terminal cap to the light bulb. However, when manufacturing the above-mentioned jacket tube from ceramic, etc., such conventional terminal caps are made by filling powder, which is a mixture of raw ceramic powder and a binder, into the recesses of the lower mold and pressurizing it with the upper mold. Then, since the compressed length at both ends is different between the part where the fixing groove and the cut groove are present and the other part, the pressing force per unit length becomes uneven, causing a difference in the density of the ceramic raw powder. . Therefore, a difference in sintering shrinkage occurs in the subsequent sintering process, resulting in problems such as dimensional defects, cracks, and warping of the outer tube. Furthermore, when a relatively strong rotational force is applied to the fixing groove when attaching the light bulb to a socket, the crushing sealing portion of the glass bulb of the light bulb may be damaged.

Furthermore, although the concave and convex grooves provided in the outer tube continuously in the axial direction on the inner surface of the terminal cap prevent the metal terminals inserted into the groove from shifting and allow accurate positioning, the concave and convex grooves in the outer tube Because the metal terminal becomes thinner, it is more likely to crack vertically along the grooves, and adhesives such as ceramics are sucked up along the grooves and cover the contact surface of the metal terminal with the socket, causing poor conductivity. Another problem was that the adhesive force between the outer tube and the metal terminal was likely to be weak.

[The aim of the invention]

The present invention has been developed to address the above-mentioned problems, and can prevent dimensional defects, cracks, and warping of the outer tube, prevent damage to the crushed sealing part of the glass bulb, and prevent poor conduction. To provide an improved tubular incandescent light bulb that causes less light generation, securely fixes a terminal cap to a glass bulb, and easily controls the irradiation direction to obtain a predetermined light distribution.

[Summary of the idea]

In the present invention, the terminal cap is bonded to the end face of the crushed sealing part of the tubular glass bulb, and the metal terminal is fitted with a jacket tube made of an insulating material, and the jacket tube faces the end face of the sealing part of the glass bulb. This is a tubular incandescent light bulb characterized in that one end surface is an uneven surface and the other end surface is formed with a plurality of pairs of opposing grooves.

[Example of idea]

The details of the present invention are shown in FIGS. 1 to 3, and the plan view, front view, and rear view of the outer tube of the terminal cap used in the embodiment of the present invention are shown in FIG. 4, and the embodiment of the present invention shown in FIG. This will be explained with reference to a partially cutaway front view.

A tungsten filament 6, the coil portion of which is not shown, is stretched along the axis inside the tubular glass bulb 5, and a metal foil 7 made of molybdenum or the like welded to one end of the filament 6 is crushed and sealed. A crush sealing portion 8 is formed. An external lead 9 is welded to the other end of the metal foil 7 and led out of the bulb 5, and a metal terminal 10 is connected to the tip of the external lead 9. A jacket tube 11 made of an insulating material such as ceramic is fitted into the metal terminal 10 to constitute a terminal cap 12. The outer tube 11 is bonded to the end surface of the crush sealing portion 8 of the glass bulb 5 with an inorganic adhesive 13. The above-mentioned mantle tube 11
As shown in FIGS. 1 to 3, an uneven surface 14 is formed on one end surface of the outer tube 11 facing the end surface of the sealing part 8 of the glass bulb 5, and an uneven surface 14 is formed on the other end surface. A cut groove 15 is formed.
The cut grooves 15 are provided in plural pairs, for example, in FIG.
There is a counter. The uneven surface 14 is formed radially as shown in the third figure, and the length a of the mantle tube 11 is 5 mm.
or 10 mm, the depth b of the uneven surface 14 is 0.5
mm to 1 mm is preferable, and the shape of the unevenness is the second
As shown in the figure, sawtooth or corrugated shapes are easy to manufacture.

By placing the outer tube 11 over the metal terminal 10 of the glass bulb 5 and bonding it with an adhesive 13 as shown in FIG. It is fixed to cover the end face of the sealing part 8.

Since the present invention has the above-described structure, the difference in density of the raw ceramic powder during pressure forming of the outer tube is reduced, and there is no occurrence of dimensional defects, cracks, or warping, and mass production is possible. According to experiments conducted by the inventors of the present invention, it was confirmed that the presence of the kerf causes no practical problems at all, and that it is easy to position it when installing it in a socket.

In addition, when a tube-shaped light bulb is installed in a socket, if a large rotational moment is applied, the crushing sealing part of the glass bulb in the conventional jacket tube will be destroyed and the bulb will become unusable, but in the bulb of this invention, the cement The glass bulb is not damaged because the outer tube is detached when it is broken, and therefore the bulb can be used again by replacing the terminal cap.

[Effect of idea]

In the present invention, the terminal cap is bonded to the end face of the crushed sealing part of the tubular glass bulb, and the metal terminal is fitted with a jacket tube made of an insulating material, and the jacket tube faces the end face of the sealing part of the glass bulb. A tubular incandescent light bulb characterized in that one end surface is an uneven surface and the other end surface is formed with a plurality of pairs of opposing grooves, and as described above, during pressure forming of the outer tube. There are no dimensional defects, cracks, or warping, and when a tube-shaped light bulb is used, the cement breaks and the outer tube separates before the glass bulb is destroyed, which prevents the glass bulb from breaking when a large rotational moment is applied. In addition, since there is no vertical cracking of the mantle tube and the work of attaching the mantle tube is easy, even a green operator can do the work.The mantle tube can be attached in any direction on the bulb, so the tungsten filament can be attached to the glass. Even if the valve is eccentric with respect to the valve axis, it has the effect that it is possible to install the mantle tube after confirming in advance the direction in which the eccentricity is small.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and the shape of the unevenness on the uneven surface of the mantle tube may be continuous spherical or oval rather than sawtooth or wavy, and the number of opposing grooves is not limited to two pairs. .

[Brief explanation of the drawing]

Figures 1, 2, and 3 are respectively a plan view, a front view, and a rear view of the outer tube of a terminal cap used in an embodiment of the tube-type incandescent light bulb of the present invention, and Figure 4 is a view of the tube of the present invention. A partially cutaway front view of an example of a shaped incandescent light bulb,
FIGS. 5 and 6 are a longitudinal sectional view and a rear view, respectively, of the outer tube of a terminal cap used in an example of a conventional tubular incandescent light bulb. 5...Tubular glass bulb, 6...Tungsten filament, 8...Crushing sealing part, 13...Adhesive, 12...Terminal cap, 10...Metal terminal,
11... Mantle tube, 14... Uneven surface, 15... Cut groove.

Claims (1)

[Scope of utility model registration request] A tungsten filament is stretched along the axis within a tubular glass bulb, and terminal caps are bonded to the end faces of the crushed seals at both ends of the glass bulb with an adhesive, and the terminal caps are made of metal. A mantle tube made of an insulating material is fitted to the terminal, and one end surface of the mantle tube has an uneven surface and is adhered to the end surface of the sealing part with an adhesive, and the other end surface has a plurality of pairs of opposing ends. A tube-shaped incandescent light bulb characterized by having a groove formed therein.