US2741747A - Panel lamp socket of insulation having opening engaging resilient fingers - Google Patents

Description

April 10, 1956 R C WOOFTER 2,741,747

PANEL LAMP S OCKET OF INSULATION HAVING OPENING ENGAGING RESILIEZNT FINGERS Filed March 11, 1954 2 Sheets-Sheet l 3e 40 42 2O 6 3o 4 iJ J I so I i I i I; 5 if I 50 I 76 38 78 I8 64 74 Q 2Q 54 58 60 R D IN! 'ENTOR.

0 C, wooffer 66 Fig.2 62

His Attorney April 1956 R. c. WOOFTER PANEL LAMP SOCKET OF INSULATION HAVING OPENING ENGAGING RESILIENT FINGERS 2 Sheets-Sheet 2 Filed March 11, 1954 o2 INVENTOR.

Robert C. Wooffer HIS Attorney United States Patent 7' PANEL LAMP SOCKET OF INSULATION OPENING ENGAGING RESILIENT FINGERS Robert C. Woofter, Cortland, Ohio, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Application March 11, 1954, Serial No. 415,553

9 Claims. (Cl. 339-128) This invention relates to lamp sockets and, more particularly, to lamp sockets adapted to be supported on the dash of an automotive vehicle, and adapted to receive light bulbs which serve to illuminate various instruments such as ammeters, pressuare gauges of various sorts and other generally similar indicating devices.

Some indicating lamps of this general type can be grounded through the supporting panel. Sockets for these lamps can be made of metal relatively cheaply and are satisfactory, but others have to employ a return circuit which is insulated from the ground metal of the car. As is well known, lamp sockets for supporting indicating lamps of this character generally have an insulated wire entering the end of the socket opposite to that in which the lamp is mounted, which is insulated from the socket and terminates in a button contact which engages the end of the lamp bulb. The return circuit is through the side of the lamp base to the socket in which the lamp is held. If the return to ground is through the supporting panel, the socket is mounted directly in the panel and is in metallic contact therewith.

On the other hand, if the return circuit must be insulated from the panel, complications arise because it be comes necessary, if metal lamp sockets are employed, to provide an outer housing for supporting the lamp, which is mounted in the supporting panel and in metallic contact therewith, but is insulated from the lamp socket itself, which is positioned within the outer housing. Where a construction of this kind is required, the cost is much more than that of the standard socket which is grounded through the support, and cost becomes an item of major consideration.

It is, therefore, the primary object of the present invention to provide a lamp socket for an indicating light which can be readily supported in fixed position in a metal supporting panel, but in which the return circuit is insulated from said panel, which is of durable construction and which can be manufactured at relatively low cost.

It is an additional object of the invention to provide a lamp socket of the character referred to in which the lamp is grounded through the supporting panel but not through the lamp socket itself, whichis of durable construction but can be made at low cost.

These objects are accomplished according to the present invention by the provision of a lamp socket formed of nylon, Bakelite or some other suitable hard plastic which is, itself, supported directly in the metal instrument panel and insulates the lamp bulb from the panel. This socket is provided with resilient fingers which snap into an opening in the supporting panel and hold the socket in position in the opening, said socket having a plurality of chambers formed therein into which conductors extend and which receive terminals that contact, respectively, the end and side of the base of the lampbulb.

Further objects and advantages of the present invention will be apparent from the following descriptionrefcrence being had to the accompanying drawings wherein 2,741,747 Patented Apr. 10, 1956 Figure 1 is an elevation of a socket constructed in accordance with the present invention, showing the light bulb in position and one of the conductors;

Figure 2 is a section on the line 2-2 of Figure 1;

Figure 3 is an elevation of the lamp socket of Figure I seen from the right in Figure 1; L

Figure 4 is an elevation of the lamp socket of Figure 1 seen from the left; V

Figure 5 is a detail view of the terminal used on one of the conductors associated with the lamp socket;

' Figure 6 is a view similar to Figure l of a modified form of the invention; and I Figure 7 is a detail view of a conducting member used with the device shown in Figure 6.

As shown in the drawings, the supporting instrument panel is designated 2 and has an opening 4 in which the lamp socket is supported. The socket has a body portion 6 from which a flange 8 integral therewith projects and when the socket is in assembled position, the flange engages the rear face of the panel 2. Also integral with the body portion 6 and extending through the opening when the socket is mounted in its supporting panel are resilient fingers 10. These fingers are arcuate in form, as shown in Fig. 3, and while four are shown in such figure, there may be a larger or smaller number. Such fingers are inwardly tapered adjacent the ends, as indicated at 12 and are slightly outwardly tapered adjacent the supporting panel as indicated at 14. The inward taper of the fingers is provided to facilitate insertion in the opening 4 and the outward taper 14- is eifective to retain the socket in position after insertion in such open- 1ng.

At the right end of the socket, as shown in Fig. 2 is a relatively large chamber 16 in which the associated light bulb is positioned. The bulb has the usual cylindrical base 18, generally of brass, which constitutes one contact, and a second contact 2!) of conventional type is mounted on the end of the base 18, but separated therefrom by insulating material 22. As more fully described later, the contact 20 is engaged by a terminal on a conductor extending to some suitable source of current and the :base 18 is engaged bya terminal on a second conductor which forms the returncircuit from the lamp to the current source.

In the wall of the body portion 6' of the socket is a bayonet slot 24 having an axial portion 26 and a transverse portion 28 which is adapted to be engaged by a pin or lug 30 extending from the base 18 to retain the lamp in proper position in the socket, in the conventional manner.

Connecting with the chamber 16 is a passage 32 of smaller diameter than said chamber, having a tapered opening 34 of still smaller size at the end thereof, through which one of the conductors of the lamp circuit extends. This conductor includes a wire 36 having a button terminal 38 secured thereto by crimping, or in any other suitable way, and a cover 49 of any suitable insulating material around the wire. The. tapered opening 3% is of such size that the insulated conductor fits loosely therein so that it can be easily inserted in the socket. Positioned in the passage 32 and surrounding the conductor is a helical spring 42, one end of which engages the terminal 38 while the other end engages a shoulder 44 formed at the junction of the passage 32 and the tapered opening 34. Such spring holds the terminal 38 in engagement with the contact 20 with considerable pressure so as to insure a good contact.

Formed in the socket at the lower side thereof, as

3 shown in Fig. 2, is a chamber or passage designated generally by the reference numeral 50. The shape of this chamber is best shown in Figs. 3 and 4. Its inner face 52 is fiat and this face terminates at a point about midway of the length of the chambersothat from that point to the right, as seen in Fig. 2, the chamber 50 merges with the chamber 16 so that there 'is no dividing wall between the two chambers but, instead, anopening is provided through which contact is made between the base 18 and a terminal which is adapted to be received in the chamber 50. The wall of the chamber opposite'the surface 50 is a curved surface 54 and extending to the right and left from the chamber 50, as seen in Fig. 3, are two slots 56 and 58, respectively, which are provided for a purpose more fully explained later. At the left end of the surface 52, a shoulder 60 .is formed while at the right end of slot 58, as seen in Fig. 2, such slot is enlarged to form a shoulder 62 for a purpose specified later.

As already stated, a terminal attached to the return conductor is adapted to be received in the chamber 50, and this terminal, as a whole, is designated 59.: This conductor comprises a wire 64, covered by suitable insulation 66. The terminal clip is best shown in Figs. 3 and'S, is formed preferably of brass and the main portion of the terminal at the right of Fig. has a somewhat U-shaped cross-section as indicated at 68, with projecting wings or flanges 70 and 72 which engage the slots 56 and 58, respectively, when the terminal is positioned in the chamber 50. Ears 74 are crimped around the insulation 66 and ears 76 are crimped around a bare part of the wire 64 itself, which extends beyond the end of the insulation. A tang 78 is punched out of the wing 72 and bent downwardly, as seen in Fig. 2, to engage the shoulder 62 and hold the terminal clip in position in the lamp socket after it has been inserted in the chamber 50, while a tang 80 bent upwardly from the terminal stops its movement to the right when it reaches the proper posiu'on in said chamber. In other words, these two tangs 78 and 80 retain the terminal in its proper position in chamber 50, as shown in Fig. 2. i

The terminal 59 has a bayonet slot 82 which is engaged by a lug 84 projecting from the base 18 at a point diametrically opposite the lug 30. This slot is so formed that a part of the side wall of the U-shaped portion of the terminal is cut away, as indicated at 86, so that as the lamp is rotated to engage the lug 30 with the transverse part 28 of the bayonet slot 24, the lug 84 can pass into the slot 82 through this cut-away portion of the side wall of terminal 59. The slot is also provided with a curved surface 88 which is engaged by lug 84 when the lamp is rotated to its proper position and the lug 30 engages the notch 90'formed in one side of the slot 24 in the pastic lamp socket.

When in such position, current can pass to the lamp through conductor 36, terminal 38 and contact 20, and thence to the current source through the return circuit comprising lug 84, terminal 59 and the conductor 64, while the lamp is completely insulated from the panel 2 by means of the plastic lamp socket in which the lamp is mounted so that there is no contact between any part of the lamp and such supporting panel.

In the modified form of the invention shown in Figs. 6 and 7 the construction of all the elements is the same as that previously described except the return circuit. Instead of having a second conductor leading back to the source of current, the lamp is grounded directly through the supporting panel 2 in which the plastic lamp socket is mounted in the manner previously described. In this form of the device, no conductor comparable to 64 extends into the chamber 50 but, instead, there is positioned therein a conducting element which is of somewhat the same construction as the terminal clip 59 and electrically connects the base 18 of the lamp directly with the panel 2. This conducting element, which is designated generally by the reference number 109, has a U-shaped body part 68, wings or flanges of the same form as 70 and 72 which engage slots of the same form as 56 and 58 previ ously described. The element 100 also has tangs 78 and 89 which engage, respectively, shoulders 62 and 69 to hold the element 104 in proper position. It is also provided with a bayonet slot 82 of the same form as that previously described and through which the lug 84 extends when the lamp is properly positioned. Indeed, the only difference between the contact element 100 and the terminal clip 5) resides in the omission of the ears 74 and 76 by means of which the terminal 59 is attached to the conductor and the addition of a contact finger which engages the panel 2 to establish electrical connection between the lug 84 and the panel. This finger is indicated at 102 and is a spring finger, preferably of brass, which is integral with the element 100 and which extends to the right in Fig. 6, and is curved outwardly so as to engage the panel 2 when properly positioned in chamber 50. The lug 84 engages the edge of the bayonet slot 82 so that the member 100 establishes electrical connection between the base 18 of the lamp and panel 2. This molded plastic socket with the conducting element 109 is equally efficient and much cheaper to make than the metal socket conventionally employed with indicating lamps which are grounded through the supporting instrument panel.

While the embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. An electric lamp socket formed of suitable insulating material having a chamber formed therein adapted to receive the base of an electric light bulb, resilient fingers extending axially therefrom and adapted to engage an opening formed in a supporting panel for retaining said socket in position on the panel, a second chamber in said socket arranged axially with reference to said first chamber and communicating therewith which is adapted to receive a conductor having a terminal on the end thereof for engagement with a contact formed on the end of said light bulb base, and a third chamber in said socket in substantially parallel relation to said first chamber and having a first opening communicating with said first chamher and a second opening in one end thereof adapted to receive a terminal connected to a second conductor, said terminal being adapted to engage the side of the light bulb base through said first opening when the terminal is positioned in said third chamber.

2. An electric lamp socket formed of suitable insulating material having a chamber formed therein to receive the base of an electric light bulb having a contact formed on the end of said base and a second contact projecting from the side of said base, resilient fingers of insulating material extending axially from said socket and adapted to engage an opening formed in a supporting panel for retaining said socket in position on said panel, a second chamber in said socket arranged axially with respect to said first chamber and communicating therewith, said chamber being adapted to receive a conductor having an enlarged terminal on the end thereof and a spring for holding said terminal in engagement with the first-mentioned contact, and a third chamber in said socket in substantially parallel relation to said first chamber and having a first opening communicating with said first chamber into which said second-mentioned contact projects when the light bulb is positioned in the socket, said third chamber having a second opening in one end thereof adapted to receive a terminal connected to a second conductor, said terminal being adapted to engage said second contact when the terminal is positioned in said chamber.

3. An electric lamp socket formed of suitable insulating material having a chamber formed therein to receive the base of an electric light bulb having a contact formed on the end of said base and a second contact projecting from the side of said base, resilientfingers of insulating material extending axially from said socket and adapted to engage an opening formed in a supporting panel for retaining said socket in position on said panel, a second chamber in said socket arranged axially with respect to said first chamber and communicating therewith, said chamber being adapted to receive a conductor having an enlarged terminal on the end thereof and a spring for holding said terminal in engagement with the first-mentioned contact, a third chamber in said socket in substantially parallel relation to said first chamber and having a first opening communicating with said first chamber into which said second contact projects When the light bulb is positioned in the socket, said third chamber having a second opening in one end thereof adapted to receive a terminal provided with a projecting tang and engageable with the second contact when the terminal is positioned in said chamber, and a shoulder formed in the wall of said third chamber to hold the second terminal in contacting position.

4. An electric lamp socket formed of suitable insulating material having a chamber formed therein provided with a lamp retaining slot in the wall thereof and adapted to receive the base of an electric light bulb having contacts formed on the end and side thereof, and a lug projecting from the side of said base and engageable with said slot to hold the bulb in position in said base, resilient fingers of insulating material extending axially from said socket and adapted to engage an opening formed in a supporting panel for retaining said socket in position on said panel, a second chamber in said socket arranged axially with respect to said first chamber and communicating therewith, said chamber being adapted to receive a conductor having an enalrged terminal on the end thereof and a spring for holding said terminal in engagement with the first-mentioned contact, a third chamber in said socket in substantially parallel relation to said first chamber and having a first opening communicating with said first chamber into which said second contact projects when the light bulb is positioned in the socket, said third chamber having a second opening in one end thereof adapted to receive a terminal provided with a projecting tang and engageable with the second contact when the terminal is positioned in said chamber, and a shoulder formed in the wall of said third chamber to hold the second terminal in contac ting position.

5. An electric lamp socket formed of suitable insulating material having a chamber formed therein adapted to receive the base of an electric light bulb, resilient fingers extending axially therefrom and adapted to engage an opening formed in a supporting panel for retaining said socket in position on the panel, a second chamber in said socket arranged axially with reference to said first chambar and communicating therewith, said second chamber being of lesser diameter than the first chamber but large enough to receive a terminal secured to an electrical conductor, a passage through which the conductor is adapted to extend and of smaller size than the second chamber so as to form a shoulder at the junction of said passage and a chamber, said shoulder being engageable by one end of a spring adapted to be positioned between said shoulder and the terminal and effective to hold said terminal in engagement with the end of the light bulb base, and a third chamber in said socket in substantially parallel relation to said first chamber and having an opening communicating with said first chamber, said third chamber being adapted to receive a terminal effective to engage the side of the light bulb through said opening connecting the first and third chambers, when the terminal is positioned in said third chamber.

6. In combination, an electric lamp socket formed of suitable insulating material having a chamber formed therein, an electric light bulb having a base received in said chamber when the bulb is supported in the socket, means for retaining the bulb in position in said socket,

resilient fingers extending axially from the socket and adapted to engage an opening formed in a supporting panel for retaining said socket in position on the panel, a second chamber in said socket arranged axially with reference to the first chamber and communicating therewith, a conductor extending into said second chamber, a terminal secured to the end thereof and positioned within said second chamber, a spring in said second chamber for holding said terminal in engagement with the end of the light bulb base, a third chamber in said socket substantially parallel with the first chamber and having a first opening communicating therewith, a second conductor extending into said third chamber through a second opening in one end thereof, a terminal secured to said second conductor and positioned in said third chamber in electrical contact with the side of the light bulb base through said first opening.

7. In combination, an electric lamp socket formed of suitable insulating material having a chamber formed therein, an electric light bulb having a base received in said chamber when the bulb is supported in the socket, means for retaining the bulb in position in said socket, resilient fingers extending axially from the socket and adapted to engage an opening formed in a supporting panel for retaining said socket in position on the panel, a second chamber in said socket arranged axially with reference to the first chamber and communicating therewith, a passage connecting with said second chamber and of smaller size than said chamber whereby a shoulder is formed at the junction of said passage and the second chamber, a conductor extending through said passage and into said chamber, a terminal secured to said conductor and positioned in said second chamber, a flange on said terminal of greater diameter than said passage, a spring positioned in said second chamber between the shoulder and flange for holding the terminal in engagement with the end of the light bulb base, a third chamber in said socket substantially parallel with the first chamber, said third chamber having a first opening in the wall thereof communicating with the first chamber and a shoulder on the wall thereof, a second conductor extending into said chamber through on opening in one end thereof, a terminal secured to said second conductor and positioned in said third chamber in electrical contact with the side of the light bulb base through said first opening, and means on said terminal for engaging said shoulder to retain the terminal in position in said third chamber.

8. An electric lamp socket formed of suitable insulating material having a chamber formed therein adapted to receive the base of an electric light bulb, resilient fingers extending axially therefrom and adapted to engage an opening formed in a supporting panel for retaining said socket in position on the panel, a second chamber in said socket arranged axially with reference to said first chamber and communicating therewith which is adapted to receive a conductor having a terminal on the end thereof for engagement with a contact formed on the end of said light bulb base, and a third chamber in said socket in sub stantially parallel relation to said first chamber and having a first opening communicating with said first chamber, said third chamber having a second opening adapted to receive a conducting member provided with a terminal so formed as to engage the side of the light bulb base through said first opening and to engage the edge of the socket retaining opening in the supporting panel when said conducting member is positioned in said third chamher.

9. A lamp socket, comprising, a body of electrical insulating material having a cylindrical chamber portion adapted to receive the base of a lamp bulb and a coaxially extending chamber portion of lesser diameter than the first portion and contiguous with the first portion, said first chamber portion being open ended at one end of said body and said second chamber portion being open ended at the opposite end of said body to effect thereby 7 a through passage through the said body, a third chamber portion in said body axially parallel with said first chamber portion and tangent to said first chamber portion to effect a longitudinally extending opening in said body between said first'and third chamber portions, said third chamber portion having facing Wall portions extending parallel with each other and axially parallel with said first chamber portion, each of said facing wall portions having a recess therein extending longitudinally of the said third chamber portion and parallel to the recess in the facing Wall portion, said body having an axial, longitudinal slot extending inwardly thereof from the open end of said first chamber portion and connecting with a slot disposed transversely in said body between the first mentioned slot and the said opening between the said first and third chamber portions.

References Cited in the file of this patent UNITED STATES PATENTS 2,283,934 lorgensen May 26, 1942 2,646,477 Heterick July 21, 1951 2,664,458 Rapata Dec. 29, 1953 FOREIGN PATENTS 481,075 Great Britain Mar. 4, 1938

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