Background of the Invention
The amount of electrical energy consumed by exit lamps, table lamps (and wall and ceiling lamps), safety lamps, and security lamps is enormous. Some of these lamps burn night and day, every day of the year. The energy consumption may be reduced drastically by switching from incandescent lamps to fluorescent lamps, but there are great numbers of existing lamp fixtures that are constructed and sized for conventional incandescent lamp blubs. Because the replacement of such existing incandescent lamp fixtures would be prohibitively expensive, attempts have been made to provide small-size fluorescent lamps in combination with screw-type plugs adapted to thread into incandescent lamp sockets in existing fixtures. However, such substitute combinations are generally too large to fit into existing incandescent lamp fixtures for exit lamps, etc.
Compact fluorescent lamps are made by several companies. For example, one is manufactured under the trademark DULUX by Osram Company of Germany (one such lamp is shown at the top of FIG. 3 of the present drawings). Such lamps have starters located in plastic housings connected to the bases of the lamps. The starter housings project downwardly well below the pins to which electrical connections are made.
There are also on the market, in addition to such compact fluorescent lamps, mass-manufactured electrical-connector plugs adapted to screw into conventional sockets for incandescent lamp bulbs. Such plugs, one of which is shown in FIG. 2a of the present drawings, are desirable to use because the startup costs for manufacture of compact fluorescent lamp combinations are minimized where existing, on-the-market parts (such as that shown in FIG. 2a) can be utilized.
A prior-art approach to combining the compact fluorescent lamps with the screw plug shown in FIG. 2a is illustrated in FIG. 1 of the present drawings. As is there illustrated, the prior art employs an external extra socket (numbered 46) which receives both the starter portion of the lamp and the contact pins thereof. Such external socket is, in turn, associated with the screw plug of FIG. 2a, and there is associated therewith a "ballast" coil (inductor) which is matched to the fluorescent bulb. The ballast is incorporated in a housing as illustrated in FIG. 1.
A major problem is that the assembly of FIG. 1 is not only relatively expensive, but--much more importantly--will not fit in a very large proportion of incandescent lighting fixtures now in place relative to exit lamps, table lamps, etc. Thus, the degree of utilization of the prior-art approach of FIG. 1 is restricted to a great extent.
In accordance with the method of the present invention, which produces the compact fluorescent lamp combination shown in FIG. 2, start-up cost is also reduced while at the same time making the entire combination sufficiently small that it may be received in the vast majority of existing incandescent lighting fixtures used for exit lamps, table lamps, etc.
cl BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view indicating a prior-art fluorescent lamp assembly for screwing into an incandescent lamp-bulb socket;
FIG. 2 is an isometric view of the present, reduced-sized fluorescent lamp combination for screwing into such a socket;
FIG. 2a is an isometric view of the prior-art plug employed in the assembly of FIG. 1 and also (in modified form) in the present invention;
FIG. 3 is an exploded isometric view of the present compact fluorescent lamp combination;
FIG. 4 is a horizontal sectional view taken on line 4--4 of FIG. 5; and
FIG. 5 is a view, primarily in vertical section, taken generally on the plane indicated at 5--5 of FIG. 4; and
FIG. 5b is a wiring diagram.
Description of the Preferred Embodiment
Referring first to the upper portion of FIG. 3, there is illustrated one of the compact fluorescent lamps. This has a U-shaped tube 10 with parallel arms. There is a metal base portion 11 connected to the arm ends. An elongated synthetic resin housing 12 projects downwardly from the base, in the opposite direction from the arms. Housing 12 contains the starter portion of the lamp.
Projecting downwardly from overhanging flange portions of starting housing 12 are metal pins 13 which provide electrical contact to the fluorescent lamp assembly, one such pin 13 being generally beneath each arm of the U.
The prior-art screw plug shown in FIG. 2a has a metal screw portion 14, and a metal button portion 15 disposed coaxially of and below portion 14, both portions 14 and 15 being adapted for insertion into a conventional screw-socket for an incandescent light bulb. Metal connector portions 14, 15 are mounted on a hollow cylindrical synthetic-resin body 16 having an upper flange portion 17. The upper flange portion 17 is recessed on the upper side thereof to form a single upper recess. At opposite regions of flange portion 17, diametrally of body 16, there are integral, internal boss portions 18 each of which is vertically apertured at 19 to receive a rivet or other fastener.
The boss portions 18 project towards each other, within the recess in flange 17. They, and the peripheral or side wall which is formed by the recessed configuration of the upper flange portion 17, cooperate with each other to define recess regions 21, there being two such regions adjacent each of the bosses 18.
Description of the Present Method and Combination
There thus having been described the prior-art compact fluorescent lamp, and also the prior-art screw plug, there will now be described the method of creating a compact, inexpensive combination thereof--which combination will fit into the great majority of existing lamp-fixture sockets for incandescent light bulbs at exit signs, etc.
As the first step in the method, opposed side wall regions of the upper flange portion 17 of body 16 are cut out to form indent regions 23 illustrated at the lower portion of FIG. 3.
Thereafter, a first insulator layer 24 is nested into the recessed flange portion 17 of body 16. Layer 24 may be formed of insulating fibrous material, insulating synthetic resin, etc. As shown in the lower region of FIG. 3, layer 24 has protuberant side-edge regions 26 adapted to nest into indent regions 23. Layer 24 also has recessed or indented regions 27 shaped to receive the boss portions 18. The depths of indent regions 23, and the thickness of first layer 24, are preferably such that the upper surface of layer 24 is flush with the rim of flange 17 of body 16, as shown in FIG. 5.
As the next step in the method, a second insulator layer, numbered 28, is mounted over first layer 24 in flatwise engagement therewith. The periphery of second layer 28 is shaped correspondingly to the shape of the rim of flange 17 of body 16, prior to indentation of such rim.
As the next step, the insulating layers are secured to each other and to flange 17 by rivets (FIGS. 2-4) that extend downwardly through holes 31 in layer 28 and also through the apertures 19 in bosses 18.
The same rivets 29 are also caused to extend downwardly through holes 32 in a generally Y-shaped sheet-metal yoke 33. The arms of yoke 33 fit around cylindrical body 16, and the base or stem portion of the yoke is riveted to the underside of the housing of a "ballast" coil or inductor 34. Inductor 34 perferably has upper and lower open-ended--at their adjacent ends--housing portions 35 and 36 which seat over the actual winding, such housing portions being secured together by insulating tape as shown at 37. The indicated housing and tape construction permits different length coils to be employed without substantial increase in the cost of manufacture, by varying the gap between the open ends of housing portions attached to different sizes of fluorescent lamps.
According to an important aspect of the present method and combination, the fluorescent lamp is not so oriented as to be parallel to a line extending through the centers of apertures 19 diametrally of cylindrical body 16. Instead, the fluorescent lamp is so turned that a plane containing the axes of the parallel lamp tubes (arms) lies at an acute angle to the above-indicated diametral line extending through apertures 19. As an example, such acute angle may be on the order of 35.degree. relative to such diametral line.
Referring to the upper portion of FIG. 3, and to FIG. 4, the starter housing 12 is rectangular in horizontal section and has its major axis perpendicular to a plane containing the axes of both arms of U-tube 10. Therefore, to achieve the described angular orientation of the U-tube, the housing 12 is caused to be inserted through registered rectangular openings 38 and 39 in insulator layers 24 and 28, such openings being oriented with their major axes complementary to the above-indicated angle of U-tube 10. Thus, in the stated specific example, the major axes of openings 38 and 39 are about 55.degree. from the diametral line passing through the centers of apertures 19.
Openings 38 and 39 are shaped and sized to snugly receive starter housing 12, and act as supporting socket means for the lamp. There are recesses 40 in layers 24 and 28 at the ends of openings 38 and 39, and which loosely receive side protuberances 41 formed integrally on the starter housing 12 of the fluorescent lamp.
There will next be described the electrical connector and wiring aspects of the present method and combination.
Insulator layers 24 and 28 are formed with registered holes 42 and 43 adated to receive the metal pins 13 which are part of the compact fluorescent lamp. The holes 42, 43 are adjacent the side edges of insulator openings 38 and 39. The underside of the upper insulator (second insulator) 28 is recessed or counterbored around its holes 43, so as to receive the upper portions of metal pin sockets 44 which are fit into holes 42 in the first or lower insulator 24. Such sockets are pressed into the insulator 24 prior to mounting thereof, are wired to remaining elements of the combination as next described, and then are covered by the second insulator layer 28 so as to eliminate any shock hazard.
The fluorescent lamp and the ballast are caused to be in series-circuit relationship relative to each other, between screw portion 14 and button 15, as shown in FIG. 5b. Thus, a wire is connected between button 15 and one of the pin sockets 44. A second wire is connected between metal screw connector 14 and one terminal of ballast 34. The remaining terminal of the ballast is connected to the remaining pin socket 44.
The described method and construction cause the lower ends of pins 13, and the pin sockets 44 in which such pin ends are inserted, to be disposed in recess regions 21 (FIG. 3) defined between boss portions 18 and internal wall portions or the flange 17 of body 16. There is therefore adequate space, for electrical insulation purposes, between sockets 42 and the metal rivets 29 which extend through apertures 19. Thus, the assembly is electrically safe as well as highly compact, having a small vertical dimension permitting its mounting in large numbers of existing incandescent-lamp sockets at exit signs, etc.
As shown in FIG. 5, the starter housing 12 penetrates deeply into body 16, even down into the metal screw portion 14. The flange region of the starter housing seats on the upper surface of second (upper) insulating layer 28, only a short distance above the rim of flange 17 of plug body 16.
The construction and method of the present invention are to be compared with the prior art showing of FIG. 1, in which a large, separate, external socket 46 is provided between the prior-art plug (FIG. 2a) and the prior-art fluorescent lamp. In comparison to the indicated prior-art assembly (FIG. 1), the present assembly (FIG. 2) saves well over an inch in height alone, making the present assembly more nearly resemble the size of a conventional incandescent light bulb, so that (especially when clearance adjacent the incandescent light bulb are taken into account) the present assembly will, as stated above, fit into the vast majority of light fixtures of the type indicated herein.
The foregoing detailed description is to be clearly understood as given by way of illustration and example only, the spirit and scope of this invention being limited solely by the appended claims.