US 3104924 A
Description (OCR text may contain errors)
P 1963 F. E. CAPEL LAMP CONNECTOR Filed Dec. '7, 1959 FR EDER/CK f/e/wzsr CA PEL United States Patent 3,104,924 LAM]? CONNECTOR Frederick Ernest Capel, Walton-on-Thames, England, assignor to Noma Corporation, New York, N.Y., a corporation of Delaware Filed Dec. 7, 1959, Ser. No. 857,917 Claims priority, application Great Britain .Ian. 12, 1959 Claims. (Cl. 339-174) This invention relates to a lamp holder for baseless miniature lamps or bulbs adapted to be connected in series or in parallel to the electrical conductor or conductors of a decorative lighting set or the like.
It is an object of the present invention to provide a new and improved lamp holder of the character described by means of which the electrical connection between the leadin wires of the lamp and the wire or wires of the main conductor is facilitated and the points of electrical connection fully insulated.
Another object of the invention resides in the provision of a lamp holder and connector of new and improved construction having means for guiding and maintaining in properly spaced relation with respect to one another the lead-in wires of the baseless lamp and separate means for guiding and maintaining the wires of the main conductor in position for engagement with the lead-in wires of the lamp.
The above and other objects and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawing and more particularly pointed out in the appended claims.
The invention is illustrated in the accompanying drawings in which FIG. 1 is a sectional view on an enlarged scale of a lamp and lamp connector in accordance with one embodiment of the invention.
FIG. 2. is an exploded view showing the four parts including the lamp, cap, plug and lamp holder of FIG. 1.
FIGS. 3 and 4 are plan views respectively of the lamp cap and plug.
'FIGS. 5 and 6 are respectively a vertical section and plan view of a lamp holder for use in the preferred embodiment of the invention.
FIG. 7 is a perspective view showing a con-tact for use with the lamp holder of FIGS. 5 and 6.
FIG. 8 is a diagrammatic view showing two lamps forming part of a lamp set connected in series.
FIG. 9 is a vertical section of the lamp holder shown in FIGS. 5 and 6, and a modified form of cap in their cooperative relation. 7
FIG. 10 is a cross section on the line 10-10 of FIG. 9 on an enlarged scale, and
FIG. 1-1 is a top plan view of the cap shown in FIG. 9'.
In the accompanying drawings C indicates a baseless lamp as commonly used in lamp sets, in which a number of lamps are electrically connected in series by conductor wires: H indicates generally a flexible lamp holder and F the flexible leads of the conductor wires which are to be electrically connected to the lead-in wires of the lamp C through the lamp holder.
Referring now to FIGS. 14 the lamp C has two exposed lead-in wires 1 which project from the end of the glass bulb and are connected in series to the conductor wire as diagrammatically shown in FIG. 8.
The lamp C is preferably of the type having an interior short circuiting strip eg of aluminum so that in the event of a failure of a lamp in the circuit the remaining lamps will remain alight, the current being short circuited through the strip.
Hitherto one of the difiiculties experienced in handling "P V 1C6 this type of lamp has been to prevent damage to the bulb at the point of entry since if the two wires are bent backwardly so that they lie flush with the sides of the bulb itself, the seal is easily damaged in which case it causes failure of the lamp.
One feature of the present invention resides in the use of a flexible recessed lamp cap member 3 which serves the dual purpose of locating and fixing the two lead-in wires relatively to one another and to the bulb and secondly as the means of locating the bulb in the lamp holder H.
The cap 3 as shown in FIG. 2 is in the form of a cup having a recess 4 to receive the bottom end of the lamp and extending through the base or transverse wall at the bottom of the recess of the cup are two spaced openings 5 through which the lead-in wires of the lamp are threaded. When in position the protruding ends of the leadin wires are bent oppositely radially outwards :and are then return bent to extend along the outside of the cap 3 reversely to their direction of extent through the openings 5 so as to lie flush with the outer face of the cap as shown in FIG. 1. The cap thus serves to hold the two lead-in wires apart and in spaced relation to one another and locates them in relation to the bulb itself so that there is little risk of damage and they are ready to make electrical contact when placed in the lamp holder. The lamp cap 3 is conveniently formed of plastic material since this provides the necessary insulation and enables it to be manufactured by a moulding operation.
The lamp holder H which is also of plastic for the same reason comprises a tubular member which is open at its lower end 7 to receive the conductor wires and at its upper end has a socket forming bore 8 of a size to receive the lamp and the lamp cap 3.
Conveniently the body portion or shank 9 of the holder member tapers to the entry opening 7 for the conductor wires; the location of the conductor wires within the holder is preferably accomplished by means of a plug 10 in which 7 are axially extending circumferentially spaced grooves 11, 11', one for each conductor wire.
In use it will be found that the grooved plug 10 being a wedge fit in the lamp holder, ensures that brass contacts on the ends of the wires F are held in position near the top of the holder or husk as it is sometimes called in the trade and at the same time the lower ends of the contacts, where they are joined to the conductor wires are kept apart and thus fully insulated.
When the lamp assembly including the lamp and lamp cap is inserted into the holder or husk with the lamp lead-in wires positioned to make frictional engagement and electrical cont-act with the pair of brass contacts of the husk, a sound electrical connection is made, the lamp being retained in the husk solely by the gripping action of the surrounding plastic and the push fit between the contacts.
Referring now to FIGS. 5 and 6 there is shown a preferred lamp fitting in which the lamp holder consists of a tubular member 13 which is open at its lower end 13' to receive the conductor wires but in which the latter are both located and insulated from one another by internal ribs 12 which, as can be seen from FIG. 6, are diametrically opposite one another so as to form two separate compartments 14, 14' to receive the contacts on the ends of the conductor wire.
In this arrangement the contacts (see FIG. 7) may each consist of an arcuate strip of metal after the form of a pen nib so that it is a tight fit in its associated compartment 14, when inserted therein.
FIG. 7 shows one shape of contact having a wide top 16 to fit the compartment but this is not essential and other arcuate section shapes may be used.
With this arrangement it is possible to dispense with the use of a separate means i.e. the plug 10 of FIG. 2 for locating the contact wires in the lamp holder and clearly the provision of spacing meansintegral with the holder i.e. the ribs 12 on the interior wall thereof reduces the number of parts.
External ribs 17--17' may be provided on the outer surface of the holder so as to form a groove into which may be sprung an ornamental collar piece.
In order toobtain an improved interlocking efiect between the lamp cap 3, the husk 13 of FIGS. 5 and 6 and the contacts and to lock the latter in position, the lamp cap may be formed with projecting legs 20 as shown in FIG. 9, which legs are spaced from one another to provide an intervening groove receiving the ribs 12 of the husk 13. The legs 20 are bored at 5 to receive the lead-in wires.
By arranging for the lower ends of the legs to overlap the upper ends of the ribs 12-, the eflfect of pushing the lamp assembly into the husk or holder will be that the flexible legs 20 which straddle (i.e. lie at right angles to) the ribs, will be forced apart, which results in a greater pressure of the lead-in wires against the contacts.
The term flexible in claims and in the context is to be understood as including any plastic material (as distinct from metal) which may yield or flex.
What I claim is:
1. The combination with a baseless lamp having two exposed flexible wire leads; of i an insulating cap member having a recess extending inwardly from one end thereof removably receiving said lamp and having also a transverse wall at the bottom of said recess formed with two openings spaced from one another and extending from without said wall to said recess,
said wire leads respectively extending from said lamp through and outwardly beyond said wall and being bent to extend radially outwardly from said openings in opposite directions to the outsideof said cap member and also being return bent and both extending along the outside of said cap member reversely to their direction of extent through said openings;
a tubular member of insulating material having a bore extending'inwardly from one end thereof and providing a socket removably receiving said cap member;
and a pair of contacts in said socket frictionally engaging said wire leads and preventing the latter from being pulled back through said openings,
whereby said wire leads hold said lamp in said mutually cooperating guide means on said cap member and said tubular member, respectively, whereby upon insertion of said cap member in place in the socket of said tubular member the wire leads of said lamp will be positioned relative to said contacts for cooperative frictional engagement.
3. The combination as claimed in claim 2 wherein said guide means comprise a pair of opposed ribs in the socket of said tubular member extending axially thereof and a pair of opposed complementary grooves in said cap memher and extending axial-1y thereof.
4. The combination as claimed in claim 1 wherein one of said first-named and second-named members is flexible and the socket-forming bore portion of said tubular member is tapered in a direction away from its entrance to provide a wedging engagement between said first-named and second-named member-s.
5. The combination as claimed in claim 2 wherein each contact comprises an arcu-ate strip disposed along the inner surface of the socket-forming bore portion of said tubular member for cooperative frictional engagement with the reversely bent portion of a respective wire lead extending axially along the adjacent side of said base.
References Cited in the file of this patent UNITED STATES PATENTS 950,399 Dods Mar. 1, 1910 1,551,876 7 Hartmann Sept. 1, 1925 1,905,843 Foulke Apr. 25, 1933 2,025,564 Blake Dec. 24, 1935 2,032,232 Strickland Feb. 25, 1936 2,042,580 Bernfeld June 2, 1936 2,074,397 Israel Mar. 23, 1937 2,419,395 Poote a Apr. 22, 1947 2,507,462 Sellers May 9, 1950 2,677,118 Stone Apr. 27, 1954 2,733,421 Grovemiller Jan. 31, 1956 FOREIGN PATENTS 483,831 Germany Oct. 7, 1929 1,137,307 France Jan. 14, 1957