US2184856A - Electric light fixture - Google Patents

Description

, Dec. 26, 1939.

ELECTRIC LIGHT FIXTURE Filed March 3, 1937 T. A. STIFFEL 2,184,856

Patented Dec. 26, 1939 UNETED STATES ersnr orrics 2 Claims.

My invention relates to improvements in electric lighting fixtures, and particularly to the lamp and shade-holders more especially for portable lamp fixtures such as table and floor lamps.

One of the objects of my invention is to reduce the cost of, and simplify, the bulb and shadeholder assembly, and to provide a structure which is easier to handle than the usual assembly, and which requires no tools in factory assembling of the parts.

A particular object of my invention is to facilitate and expedite the wiring operations of the fixture.

These and other objects of my invention will appear from the following description and appended claims in connection with the accompanying drawing which illustrates one embodiment of my invention.

Fig. 1 is a side view in elevation of a shadeholder having a lamp socket therein and illustrating the knob of the switch key extending therefrom.

Fig. 2 is a plan section taken substantially in the line 2-2 of Fig. 1.

Fig. 3 is a vertical section substantially on the line 3-3 of Fig. 2.

Figs. 4, 5, and 6 are views of the insulating shell, the bulb socket and the shade-holder shell respectively, the latter being shown in section, and all three parts being separated but in the relation in which the shell and socket are brought into assembly in the shade-holder.

The usual or standard bulb socket comprises a socket member A, an insulating shell B which is slipped over the socket member, and an outer metal shell (not shown) which encloses the other two members and which includes a cylindrical open-ended shell member and a cap member. Such standard sockets also include an insulating disc 2 which covers the base end of the socket member within the cap. The outer shell and the cap have an interlocking connection between them. In the standard socket the socket member A consists of a cylindrical block of porcelain which carries the terminals and a cylindrical threaded member 2 for the reception of the correspondingly threaded base of the usual lamp bulb. The socket member 2 is generally smaller in diameter than the porcelain block 2a which provides a shoulder 3 where they meet, and the insulating shell B is correspondingly shouldered at 1-. The outer shell (not shown) is also correspondingly shouldered, for the purpose of holding the insulating shell and socket member in place.

When standard sockets such as just described are used in connection with shade-holders in portable lamps, it is necessary to first secure the wires 5 to the terminals and then assemble all of the parts of the socket. This assembling'includes threading the wires through the cap member and its insulating disc 5, inserting the socket member A in the insulating shell B and the outer metal shell, and locking the outer shell and cap together to complete the unit. The unit is then inserted in the shade-holder and then some provision must be made for holding the socket in place against rotation when the lamp bulb is screwed into or out of the socket.

In accordance with my invention, I eliminate the outer metal shell and cap of the standard socket .and utilize the shade-holder not only as a means for enclosing the other parts of the socket but to retain these other parts in place. The shade-holder C, shown in the drawing, is typical of any suitable structure for the purpose. In this instance it is bell-shaped at its upper portion and provided with an annular-shouldered recess 6 for the reception of the shade, and with suitable means l'a for securing the shade therein. The 25 other end portion 1 is'cylindrical in shape and of 'a diameter sufficiently larger than the diameter of the insulating shell B to provide proper clearance for the shell in the cylindrical portion "I.

The lower end 8 of the shade-holder is shown in the present instance as being reduced in diameter and formed as a flange to provide a means by I which the holder can be attached to a tube 9 for support. The means for supporting the shadeholder may be of any suitable construction. com- 5 mon inthe art. It is desirable, however, that a bottom shoulder ill be formed to serve as a stop to hold the socket parts in position at their lower end. Thus the shade-holder serves its usual function as an enclosure for the socket, and its cy- 40 lindrical portion I also serves as a substitute for the outer metal shell of the standard socket thereby eliminating the metal shell of the socket entirely.

In assembling the structure the wires 5 are 45 first connected in the usual manner to the terminals in the porcelain block 2a of the socket member A, the insulating disc I being first threaded onto the wires. The insulating'shell B is then slipped over the end of the socket memher A until its shoulder 4 bears against the shoulder 3 of the socket member. The wires are then threaded through the bottom of the shade-holder and into the tube 9 and the socket member with its shell B inserted into the cylindrical portion 1 5 of the holder. In the use of the usual standard socket, after the socket is wired it is necessary to bring the outer metal shell and its metal cap together and interlock the two, but in accordance with my invention both the metal shell and cap are entirely eliminated.

Means are provided for holding the socket member A, the insulating shell B, and the insulating disc l, snugly and firmly in place within the cylindrical portion of the shade-holder. In the present instance, this means consists of a plurality .of prongs I2 the tipends l3 of which are bluntly pointed and fairly sharp, and are positioned to project in the path of the insulating. shell B as it is inserted into the cylindrical portion 1. These prongs are preferably formed integrally with the metal of the shade-holder by slitting the metal for some distance to form tongues which are free from the shell except at their upper ends it. These struck-up tongues .or prongs are then bent inwardly to the position shown more clearly in Figs. 3 and 6, so that their tip ends, as previously stated, lie in the path of the insulating shell B as it is inserted in the socket. This construction makes the tongues or prongs springy so that as the shell is inserted they yield and allow it to pass into the cylindrical portion 1.

The prongs are so positioned that when the socket member and insulating shell are seated in the bottom of the shell portion 1, they will just pass the shoulder 3 of shell B and will spring inwardly and engage the shoulder 3, thus locking the shellagainst longitudinal movement. The sharp points of the prongs dig into the shell B to some extent and firmly hold the shell and socket member against rotation when the lamp bulb is screwed into or out of the socket, this being particularly important when keyless sockets are used. The drawing shows a standard type of key socket in which switch means are mounted in the porcelain block 2a, the switch being operated by a laterally extending shaft l5 having an operating knob It on its outer end. vWhen key sockets are used, the shade-holder portion I has a slot l! in its side wall through which the shaft l5 extends, this slot being elongated enough to permit the shaft to be easily inserted therethrough in assembling the structure. The knob is usually separable from the shaft so that the shaft will go through a narrower slot and is screwed onto the shaft after the socket is in place. Any number of the locking prongs l2 may be provided; the drawing shows three equidistantly spaced around the shell portion 1.

It will be noted that my invention is especially adapted to the use of standard lamp sockets since no change whatever is made in their construction and operation. The combined shade-holder and socket-holder is preferably made of sheet metal drawn or spun to shape and provided with integral resilient prongs or fingers arranged to yieldingly engage the socket and its insulating shell when inserted in the holder shell.

I claim:

1. In an electric light fixture .of the class described, the combination of a standard lamp socket unit comprising a terminal block having a lamp socket member secured thereto and a tubular insulating shell open at its ends and into which said terminal block and socket member are inserted through one end, said shell having means holding said block and socket member against removal through the other end, a tubular outer shell open at one end and having a seat for said lamp socket unit, and sharpened prongs instanding from the wall of said outer shell in the path of said unit permitting the insertion of the unit to its seat but adapted to become embedded in said insulating shell to prevent movement of said unit in the reverse direction, said prongs being located to substantially coincide with the insulating shell holding means when the unit is seated.

2. As an article of manufacture, a combined shade-holder and lamp socket holder formed in one piece and comprising a tubular metal shell open at one end to receive the internal unit socket member and insulating shell of a standard lamp socket, and having integral means at said open end for holding a shade, and having a reduced portion at its opposite end forming a seat for said inserted unit lamp socket, the wall of said shell portion having instanding integral resilient prongs spaced from said seat and projecting into said shell portion towards said seat to yieldingly press against said insulating shell, said prongs being sharpened to dig into and become embedded in the Wall of said insulating shell upon the tendency of any withdrawal movement thereof.

THEOPI-HLE A. STIFFEL.

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