GB1582885A

GB1582885A - Method of and an apparatus for manufacturing a bent fluorescent lamp

Info

Publication number: GB1582885A
Application number: GB2153677A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-05-21
Filing date: 1977-05-21
Publication date: 1981-01-14

Description

(54) A METHOD OF AND AN APPARATUS FOR MANUFACTURING A BENT FLUORESCENT LAMP (71) I, Osamu KAWAMURA, a sub- ject of Japan, of' Koganehara No.2-13-13, Matsudo-Shi Chiba-Ken, Japan do hereby declare the invention for which I pray that a patent' may 'be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a method and an apparatus for manufacturing a curved or bent fluorescent lamp.

Heretofore, two types of!fluorescent lamp have been commercially offered, namely elongated lamp and an annular or so-called circline fluorescent lamp. Generally, manufacture of an elongated fluorescent lamp is well known and an annular fluores- - cent lamp is manufactured by bending the.

straight lamp bulb under an appropriate heat 'treatment !with a suitable bending machine. -As a bending configuration, an annular or circline shape is convenient in design and manufacture to obtain a homogeneous quality of the product.

However, a fluorescent lamp having a complicated configuration or shape entails many difficulties in manufacture and needs cumbersome hand work which is unsuitable for mass production. Conventional linear and annular fluorescent lamps have been generally used as illumination appliances together with a decorated shade or other lamp carrier which limits illumination of the fluorescent lamp.

To compensate for the lowering of the illumination of the fluorescent lamp a num ber '6f the lamps have been used with a considerable consumption of the power.

in the rnanufacture of a fluorescent lamp in accordance with the present invention 'the conventional steps for manufacturing a straight fluorescent lamp; bulb up to the commencement of the heating step have been' ' employed and an improvement has beèn directed to the bending operation.

Namely, an elongated fluorescent lamp bulb is held at its opposite ends for heating by means of a convenient heater and softened sufficiently for bending and subsequently one of the bulb ends is held stationary while the opposite bulb end is subjected to a planetary turning for approximately 250 closing to the fixed bulb end .by slow degrees so that the linear fluorescent bulb is bent smoothly while retaining a balance of symmetry.

The curved or bent fludrescent lamp in accordance with the present invention has graceful and increased curvatures as com pared with the conventional annul'ar fluores cent lamp which makes it possible to manu -facture a fluorescent lamp of great output and illumination despite its limited space occupation.

According to one aspect of tht invention there is provided a process for manufactur ing a bent fluorescent lamp which comprises steps of preparing an elongated' straight fluorescent lamp bulb having opposite ends separated by an intermediate portion, heat ing the elongated lamp bulb, bending the bulb so that it is spirally bent in opposite directions from the longitudinal central point of the intermediate portion so that the opposite ends point in the same direction and are positioned substantially parallel to one another, exhausting the bent lamp bulb and subsequently introducing an ionizing gas thereinto, sealing and securing electric connectors to the opposite ends of the bent fluorescent lamp bulb.

In the steps of holding opposite ends of the hot lamp bulb for symmetrical bending, one end of the lamp bulb is fixed whereas the opposite end thereof is preferably sub jected to a planetary turning for approx iamately 250 so as to gradually close to the fixed end.

According to another aspect of the inven tion, there is provided an apparatus for manufacturing a bent fluorescent lamp com prising a means for preparing an elongated fluorescent lamp bulb, a turnable work disc means for sequentially presenting successive elongated fluorescent lamp bulbs at succes sive positions for heating, bending, exhaust ing, introducing an ionizing gas and subse quent sealing, bending means being pro vided at the bending position the bending means including a stationary holder for 'holding one end of the bulb, and a movable holder for holding the opposite end of the bulb, the movable holder being movable along a guide track in order to bend the elongate bulb so that it is spirally bent in opposite directions from the longitudinal mid point of bulb so that opposite ends point in the same direction and are substan tially parallel to one another.

In the foregoing apparatus, two holders of the bending means are coupled through a pantograph link which is provided with a turning transmission mechanism to obtain movement of the movable holder around the stationary holder under the operation of a reversible motor.

The stationary and movable holders are preferably provided with spiral guide chan nels for bending opposite ends of the fluorescent lamp bulb.

In order to prevent any undesired distor tion of the fluorescent lamp bulb during the bending operation, it is preferred to provide a receiving plate which is in contact with an intermediate portion of the fluorescent lamp bulb and moved along a curved track in synchronism with movement of the movable holder under the operation of the reversible motor.

According to a further aspect of the present invention there is provided a fluorescent lamp comprising an elongate fluorescent lamp bulb having opposite ends separated by an intermediate portion which is spirally bent in opposite directions from its longitudinal central point so that the opposite ends point in the same direction and are positioned substantially parallel to one another.

The opposite ends of the bent fluorescent lamp may selectively be connected to a common or independent cap inclusive of electric terminals. The common cap is com prised of an elongated casing which is provided at its one side with two openings for receiving opposite ends of the fluores cent lamp and a recess for receiving electric terminals.

Reference is now made to the accom panying drawings, in which: Figures la to e show a front elevation of a fluorescent lamp in progressive stages of bending; Figure 2 is a fragmentarily enlarged picto rial view of an apparatus for manufacturing a fluorescent lamp in accordance with the present invention; Figure 3 is a perspective view of the apparatus in accordance with the invention; Figure 4 is a longitudinally sectioned view taken along the line IV - IV of'Figure 3; Figure 4a is a sectional view taken along line IVa - IVa of Figure 4.

Figure 5 is a pictorial plan view of the guide channel member for the fluorescent lamp bulb; Figure 6 is a sectional view of the guide channel member taken along the line VI VI of Figure 5; Figure 7 is a sectional view taken along the line VII - VII of Figure 5; Figure 8 is a perspective view of the guide channel member of Figure 5; Figure 9 is a sectional view taken along the line IX - IX of Figure 5; Figure 10 is a pictorial plan view of the guide channel member of another embodiment; Figure 11 is a sectional view taken along the line XI - XI of Figure 10;, Figure 12 is a sectional view taken along the line XII - XII of Figure 5; Figure 13 is a perspective view of the fluorescent lamp manufactured in accordance with the present invention; Figure 14 is a front elevation of the fluorescent lamp of Figure 13;; Figure 15 is a lateral view of the fluorescent lamp of Figure 13; Figure 16 is a plan view of an electric connecting terminal of the fluorescent lamp obtained in accordance with the invention; Figure 17 is a cross sectional view taken along the line XVII - XVII of Figure 16; Figure 18 is a longitudinally sectioned view taken along the line XVIII - XVIII of Figure 17; Figure 19 is a sectional view of an electric connecting terminal connected with a plug socket; Figure 2Q, a to h are perspective views of a lighting fixture fabricated with use of one or more bent fluorescent lamps obtained in accordance with the present invention.

The method of preparing the bent fluorescent lamp in accordance with the invention will be hereinafter fully described in connection with the apparatus therefor.

In Figure 1, the bending operation of the fluorescent lamp bulb in accordance with the present invention is illustrated in order.

Namely, an elongate fluorescent lamp bulb 10 is heated to a temperature suitable for bending of the bulb which is approximately 700"C, and the opposite ends of the hot bulb 10 are held by means of the holders 12 and 14 as shown in Figure la. The holders 12 and 14 are swivelled symmetrically through an angle of approximately 250 in a predeter mined direction to approach each other until they come to a position over an intermediate portion of the bulb body as shbwn in Figure 13.

As illustrated in'Figure 2 a rotatable work disc 16 is provided which is' indexed intermittently to' carry an elongated fluorescent lamp bulb to successive positions so that the operations of heating, bending,-exhausting, and be'aling are successively carried out.

At first the elongated fluorescent lamp bulb is vertically held in the work disc 16 and heated a't the hefting zone by means of a heater 18 which is movable in a generally radial direction against the work'disc 16.

The heater 18 is comprised of'a heating sleeve 20 which is divided' into two parts for opening and closing 9nd a support plate 22 for ;tarrying the heating sleeve 20 and movable in synchronism with' the indexing or intermittent turning motion of the work disc 16. The fluorescent'lamp 10 heated at the heater 18 is carried by the next indexing movement of the work disc 16 to a position where the bulb is subjected to the bending operation by a bending means 2means 24.

In Iigures3 and 4, the, bending means 24 includes a mobile bed 26 and a bending mechanism 28 mounted on the bed 26 through the support members 30 and 32.

The bending mechanism 28 includes a hol der, 34 adapted to suspend one end of the vertically positioned fluorescent lamp bulb '10, a holder 36 adapted to engage the opposite end of the fluorescent lamp bulb 10 and a guide track 38 supported by support member 32 for guiding the holder 36 upwardly along an arc. The terminal end of the guide track;38 is preferably secured to the support member 30 to increase the stability thereof.The holder 34 is associated with a spiral guide channel member 40 whereas the holder 36 is associated with a spiral guide channel member 42; the holder 36 being turned along the guide track 38 and around an axis of the holder 34'by approximately 2soy. On a rigid shaft 44 of the holder 34 supporting the spiral guide channel member 40 is mounted a revolving sleeve 46.

'As shown in Figure 4, the holder 36 is connected to a frame member 48 movably connected to the guide track 38 and includes a shaft 50 rotatably mounted'in a part of the frame member 48. The holders 34 and 36 are associated with' each other through a pantograph link 52 which is provided with turning power transmission shafts 54 and 56 connected through a bevel gear mechanism 58. One end of lie power transmission shaft 56 is connected to the sleeve 46 whereas the opposite end of the power transmission shaft 54 is connected to the shaft 50. A reversible motor 60 rotatably drives the sleeve 46 through a chain 62 which in turn rotates shafts 54, 56' and 50 so that the holder 36.is caused to move along the guide track 38 as hereinbefore described.

The guide track 38 is so arranged that the radial distance between the pivotal point of the pantograph' link with frame member 48 and the stationary holder 34 is gradually reduced and by this arrangement the bending operation of the fluorescent lamp bulb 10 in accordance with the invention may be accomplished.

To turn the fluorescent lamp bulb for bending, an intermediate portion of the bulb 10 is carried by a receiver plate 64 which moves in synchronism with the movement of the pantograph link 52. The.receiver plate 64 is preferably associated with a second track 66 for guiding the receiver plate 64 to carry the intermediate portion of the bulb 10 and mounted with a support member 68 so that the receiver plate 64 is moved along the second track 66 under the operation of a reversible motor 70.

In the bending means 24, engagements between the frame 48 of the movable holder 36 and the guide track 38 and between the support member 68 of the receiver plate 64 and the track 66 are obtained with use of a conveneient number of rollers. To obtain a smooth bending operation of the fluorescent lamp bulb in accordance with the invention, reversible motors 60 and 70 may preferably be electric motors or hydraulic motors each of ,which is so designed that the driving speed is reduced on start and stop.

When the hot fluorescent lamp bulb 10 comes to the bending position, the bending means 24 is moved against the fluorescent lamp 10. 'In this operation, the holders 34, 36 and the receiver plate 64 are somewhat displaced from the contacting position with the bulb 10 as shown by the dotted line in Figure 3 and when the bed 26 arrives at the predetermined working position these hol ders 34, 36 and the receiver plate 64 are moved to the contacting position with the fluorescent lamp bulb for holding thereof.

Further, to avoid any excessive contacting pressure of the receiver plate 64 against the vertically arranged fluorescent lamp bulb, provision is made of an extended portion 72 in contact with the holder 36 so that distortion of the fluorescent lamp bulb is avoided.

The reversible motors 60 and 70 are driven synchronously and causing the mov able holder 36 to turn around the stationary holder 34 while carrying the intermediate portion of the fluorescent lamp bulb 10 through the receiver plate 64. Thus, it will be appreciated that turning of the holder 36 approximately 2500 against the holder 34 brings bending of the elongated fluorescent lamp bulb 10 from the shape a to e.

Moreover, the guide track 38 for guiding the movable holder 36 and the track 66 for guiding the receiver plate 64 are provided at their opposite ends with convenient stop pers so that when the movable holder 36 and the receiver plate 64 arrive at the terminal ends the reversible motors 60 and 70 are independently actuated to make a reverse drive for returning the holder 36 and the receiver plate 64 to their original positions.

As hereinbefore described, the holders 34 and 36 are provided with guide channel members 40 and 42 which determine the curvature of the bent fluorescent lamp bulb.

Separation of these members 40 and 42 from the curved bulb may be effected in the manner illustrated in Figures 5 to 10.

The guide channel member 42 mounted on the movable holder 36 is divided into two parts against the longitudinal direction of the fluorescent lamp 10 and one divided guide channel- member 42a abutting to the holder 36 is connected through an arm 74 to a shaft 78 of a torque actuator 76 as shown in Figure 6 whereas the divided guide channel member 42b is connected through an arm 80 to a shaft 84 of an actuator 82 as shown in Figure 7, so that the guide channel members 42a and 42b are separated from the fluorescent lamp bulb 10 under the operation of the torque actuators 76 and 82.

In Figure 6, a guide channel member 42c is provided to embrace the fluorescent lamp bulb 10 . together with the divided guide channel member 42a for preventing any undesired distortion of the bulb during the bending operation thereof.

As seen in Figure 8, the guide channel member 40 is divided into two parts along the circumference of the fluorescent lamp bulb 10 and one of the divided parts 40a is made movable with the bed 26 whereas the opposite divided guide channel member 40b is fixed together with the bent fluorescent lamp bulb 10.

As best shown in Figures 5 and 9, there are provided further divisional guide channel members 40c and 40d in which the member 40c is connected through an arm 86 to a shaft 90 of an actuator 88 as shown in Figure 9, so that the fluorescent lamp bulb 10 is conveniently removed by displacement of the divisional guide channel member 40c.

Alternatively, the guide channel member 40 is divisible along the longitudinal direction of the fluorescent lamp bulb and one of the divided parts 40e of the guide channel member adjoining to the holder 34 is connected through an arm 92 to a shaft 96 of a torque actuator 94 (Figure 10) whereas a guide channel member 40f is connected through an arm 98 to a shaft 102 of a torque actuator 100 as shown in Figure 11, so that the divided guide channel members 40e and 40f are removed from the fluorescent lamp bulb 10 under the operation of the torque actuators 94 and 100.

As shown in Figure 12 the holder 36 for holding the one end of the fluorescent lamp bulb 10 is typically comprised of holder pieces 36a and 36b which at their one ends are connected to gear segments 108, 108 which are journaled on a fixed shaft 104 and a turning shaft 106 derived from an actuator 110, so that the engagement'and disengagement of holders 36 with the fluorescent lamp bulb 10 are carried out under the operation of the actuator.

In the bending work position, the bent fluorescent lamp bulb after completion of bending by the bending means 24 is disengaged from the means 24 and transferred to the next working position by indexing the disc 16. The fluorescent lamp bulb released from the bending work position is subsequently subjected to conventional finishings including the steps of exhausting, sealing of' the bulb after introducing an ionizing gas and providing end caps for obtaining a finish product of the fluorescent lamp as best' shown in Figures 13 to 15.

In the bent fluorescent lamp obtained in accordance with the present invention, the opposite ends of the lamp are positioned side by side and these ends are mounted with a single end cap 112 as hereinafter fully described.

Namely, in Figures 16 to 18, a typical embodiment of the end cap of the invention is illustrated. The end cap 112 comprises a casing of synthetic material which is pro vided with two openings 114, 114 on' one side portion for receiving the opposite ends of the fluorescent lamp. In another side portion of the casing 112 a recess 113 is provided for providing electrodes 116 to which lead wires 118 derived from the ends of the lamp 10 are connected as shown in Figure 18. For convenience in manufacture and treatment of the end cap, it may be divisible into two parts.

Figure 19 illustrates an example of a receptacle coupled with the end cap 112 and this receptacle comprises a covering 120 having an opening 122 for passing electric wires 124 which are connected to a plug 126 fixed to the covering 120. A part of the plug 126 is extended to provide a projection'128 which is inserted into an opening 130 provided in the end cap 112. To a tip end of the projection 128 is secured a locking member 132 for fixing the receptable to the end cap 112.

As best shown in Figure 20a to h, two or more bent fluorescent lamps obtained in accordance with the present invention may be used in combination to provide a fluorescent lamp of intricate pattern and' design like a chandelier of incandescent lamps.

As hereinbefore fully described, in accordance with the invention, a fluorescent lamp of bent configuration other than the circline may be obtained conveniently by merely incorporating a bending mechanism into the conventional machines for producing the fluorescent lamp without substantially increasing the cost.

WHAT WE CLAIM IS- 1. A process for manufacturing a bent fluorescent lamp which comprises steps of preparing an elongated straight fluorescent lamp bulb having opposite ends separated by an intermediate portion, heating the elongated lamp bulb, bending the bulb so that it is spirally bent in opposite directions from the longitudinal central point of the intermediate portion so that the opposite ends point in the same direction and are positioned substantially parallel to one another, exhausting the lamp bulb and subsequently introducing an ionizing gas thereinto, sealing and securing electric connectors to the opposite ends of the bent fluorescent lamp bulb.

2. A process according to Claim 1 wherein bending of lamp bulb is achieved by holding opposite ends of the elongated hot lamp bulb in such a way that one end of the elongated lamp bulb is fixed whereas the opposite.end thereof is moved to effect bending of the bulb.

3. A fluorescent lamp comprising an elongate fluorescent lamp bulb having opposite ends separated by an intermediate portion which is spirally bent in opposite directions from its longitudinal central point so that the 'opposite ends point in the same direction and are positioned substantially parallel to one another.

4. A lamp according to Claim 3 wherein the opposite ends of the bent fluorescent lamp are connected to a common or independent cap inclusive of electric terminals.

5. 5. A lamp according to Claim 4, wherein the common cap is comprised of an elongated casing which is provided with two openings on one of its sides for receiving opposite ends of the fluorescent lamp bulb and with a recess for receiving electric terminals.

6. A fluorescent lamp substantially as herein described with reference to and as illustrated in the accompanying drawings.

7. A lighting fixture including one or more fluorescent lamps according to any of Claims 3 to 6.

8. An apparatus for manufacturing a bent fluorescent lamp comprising a means for preparing an elongated fluorescent lamp bulb, a turnable work disc means for sequentially presenting successive elongated fluorescent lamp bulbs at successive positions for heating, bending, exhausting, introducing an ionizing gas and subsequent sealing, bending means being provided at the bending position, the bending means including a stationary holder for holding one end of the bulb, and a movable holder for holding the opposite end of the bulb, the movable holder being movable along a guide track in order to bend the elongate bulb so that it is spirally bent in opposite direction from the longitudinal mid point of the bulb so that opposite ends point in the same direction and are substantially parallel to one another.

9. An apparatus according to Claim 8, wherein the stationary and movable holders of the bending means are coupled through a pantograph link which is provided with a turning transmission mechanism to obtain a movement of the movable holder around the stationary holder under the operation of a reversible motor.

10. An apparatus according to Claim 8 or 9, wherein the stationary and movable holders are provided with spiral guide channels for bending opposite ends of the fluorescent lamp bulb.

11. An apparatus according to Claim 9, wherein each guide channel is composed of seperable parts, the parts being seperable by means of a torque actuator to enable separation of the bent fluorescent lamp bulb from the bending means.

12. An apparatus according to any of Claims 8 to 11, wherein a receiving plate is provided for engaging with an intermediate portion of the fluorescent lamp bulb during the bending operation, the receiving plate 'being movable along a curved track in synchronism with the movement of the movable holder.

13. An apparatus according to any of 'Claims 8 to 12, wherein the guide track enables the movable holder to travel around the fixed holder by about 250 degree.

14. An apparatus for manufacturing a bent fluorescent lamp bulb as hereinbefore substantially described with reference to the drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. into the conventional machines for producing the fluorescent lamp without substantially increasing the cost. WHAT WE CLAIM IS-

1. A process for manufacturing a bent fluorescent lamp which comprises steps of preparing an elongated straight fluorescent lamp bulb having opposite ends separated by an intermediate portion, heating the elongated lamp bulb, bending the bulb so that it is spirally bent in opposite directions from the longitudinal central point of the intermediate portion so that the opposite ends point in the same direction and are positioned substantially parallel to one another, exhausting the lamp bulb and subsequently introducing an ionizing gas thereinto, sealing and securing electric connectors to the opposite ends of the bent fluorescent lamp bulb.