US3214724A

US3214724A - Lamp socket

Info

Publication number: US3214724A
Application number: US305036A
Authority: US
Inventors: Lawrie G Mcintosh
Original assignee: Carillon Lighting Ltd
Current assignee: Carillon Lighting Ltd
Priority date: 1963-08-28
Filing date: 1963-08-28
Publication date: 1965-10-26
Anticipated expiration: 1982-10-26

Description

Oct. 26, 1965 L, o os 3,214,724

LAMP SOCKET Filed Aug. 28, 1963 2 Sheets-Sheet 1 INVENTOR.

J Awe 6 m/ave? #mur A Home y Oct. 26, 1965 G. MCINTOSH LAMP SOCKET 2 Sheets-Sheet 2 Filed Aug. 28, 1963 Attorney United States Patent Q 3,214,724 LAMP SOCKET Lawrie G. McIntosh, Etobicoke, Ontario, Canada, assignor to Carillon Lighting Limited, Toronto, Ontario, Canada Filed Aug. 28, 1963, Ser. No. 395,036 15 Claims. (Cl. 339-99) This invention relates to a lamp socket of a unique construction, to a new and useful device for holding the parts of the housing of a lamp socket together, and to a new and useful electrical contact arrangement for a lamp socket.

Prior art types of lamp sockets generally are provided with a housing which is formed in two parts, with the parts .of the housing being held together by screws, rivets or the like. It is a disadvantage in the manufacture of such sockets that to screw together the parts of the housing of a lamp socket is a time consuming procedure, and a machine is required to perform the riveting operation, which also is a time consuming procedure.

With other types of lamp sockets a headed metal strip may be passed through the parts of the housing, the metal strip being bent over or otherwise deformed against one part of the housing to retain the parts of the housing together between the head and the deformed part. Such a mode of fastening requires the provision of a bending machine or the like, which, because it performs a separate operation, increases the time consumed in and adds to the cost of assembling the parts of the housing together. Furthermore, the deformed part is visible and detracts from the appearance of the socket.

Accordingly, one object of one aspect of this invention is to provide pre-formed holding means which only need to be inserted into the parts of the housing of a lamp socket to maintain these parts together.

A further object of a preferred embodiment of this aspect of the invention is to provide holding means for holding together the parts of the housing of a lamp socket, the holding means being formed integral with a spring clip which is employed to fasten the lamp socket to a tree branch or the like, and preferably not being visible from the side of the socket opposite to the holding means.

In the past many different types of electrical contact arrangements have been proposed for use wit-h lamp sockets. Generally speaking, the two electrical contacts of a lamp socket are completely dissimilar in shape and appearance. These electrical contacts are made separately by separate operations and then are inserted into the lamp socket and subsequently connected to electrical conductors, or are first connected to the electrical conductors and then placed in the lamp socket. I

It is an object of another aspect of this invention to provide a set of electrical cont-acts which can be made in simple steps from a single strip of material.

A further object of this aspect of the invention is to provide a set of contacts which are assembled on electrical conductors from the same side thereof, so that when the electrical contacts are positioned in the housing of a socket, the contacts are oriented in one part of the housing of the socket, enabling a recess to be provided in the other part of the housing of the socket to accommodate a tree branch or the like, thus permitting the socket to be positioned more closely towards the centre of the tree branch.

An additional object of still a further aspect of this invention is to provide a housing for a lamp socket, the housing being constructed in two parts with one part carrying die members which serve, when the parts of the housing are closed upon each other, to orient the contacts properly in the housing.

The various aspects of this invention and its advantages will become more apparent from the following detailed description taken in conjunction with the drawings? in which:

FIGURE 1 is a perspective view of a lamp socket embodying this invention;

FIGURE 2 is a section taken along line 2-2 in FIG- URE 1;

FIGURE 3 shows in section a modified form of part of a lamp socket embodying this invention;

FIGURE 4 is a view showing the manner of assembling electrical contacts embodying this invention;

FIGURES 5 and 6 are perspective views showing the interiors of the two parts of the housing of a lamp socket embodying this invention; and

FIGURE 7 is a View similar to FIGURE 5 but showing the electrical contacts and conductors in position, the part of the housing of the lamp socket shown in FIG- URE 6 being illustrated in ghost outline.

Referring to FIGURES 1-3 and 5-7, a lamp socket 1t) embodying this invention comprises a housing molded in two parts .11 and 12 of any suitable electrical insulating material. Positioned in the lamp socket are

electrical contacts

13 and 14 made of copper or any other suitable electrically conductive material.

Electrical contacts

13 and 14 will be discussed in greater detail hereinafter, but, for present purposes, it is sufiicient to note that

contacts

13 and 14 are electrically connected to wires in insulated

conductors

15 and 16 respectively by means of

insulation piercing pins

17 and 18 which penetrate the insulation of electrically insulated

conductors

15 and 16 and electrically contact the electrically conductive wires within the insulation.

Part 11 of the housing has an opening 19 extending therethrough, while part 12 of the housing has an opening 20 therein which does not extend completely through part 12 but terminates short of the outer surface of part 12 in a wall 20a, as best shown in FIGURE .2. Both openings .19 and 20 are of square cross-section.

In accordance with one aspect of this invention, a new and useful holding device 21 which is best shown in FIG- URE 2, and which is also shown in part in FIGURE 1 is provided. Holding device 21 comprises a strip 22 of spring metal which carries a spring finger 23 at one end thereof, spring finger 23 being generally hook-shaped and projecting sideways from strip 22. Strip 22 preferably is formed integral with a spring finger 24 by cutting strip 22 from spring finger 24, bend-ing strip 22 downwardly at.

approximately right angles to spring finger 24, thereby leaving an opening 25 in spring finger 24, and bending spring finger 23 to the hook-shaped configuration shown in FIGURE 2. Spring finger 24 serves as the head of holding device 21 and has a circular opening 26 therein.

In order to retain

parts

11 and 12 of the housing together, strip 22 carrying spring finger 23 is inserted into openings 1-9 and 20 to the position shown in FIGURE 2. Opening 26 in spring finger 24 co-operates with a pin 27 provided in a recess 28 in part 11 of the housing in such a manner that pin 27 restrains spring finger 24 from lateral movement with respect to part 11, while any tendency for spring finger 24 to pivot about pin 27 is prevented by the abutment of those outside edges of spring finger 24 which are adjacent opening 26 with the side walls defining recess 28. Spring finger 23 is so dimensioned that upon insertion of strip 22 into

openings

19 and 20, spring finger 23 is flexed and, therefore, in the position shown in FIG- URE 2, is biased against one side wall 29 of opening 20.

From the foregoing it will be seen that

parts

11 and 12 of the housing may be held together by the very simple operation of pressing holding device 21 into place, and that separation of

parts

11 and 12 is strongly resisted by holding device 21, since any attempt to remove holding device 21 from the position of FIGURE 2 immediately results in spring finger 23 digging into side wall 29.

Should it ever be necessary to remove holding device 21, wall a can be penetrated and a thin strip of metal slid along wall'29, thus enabling holding device 21 to be removed, but once holding device 21 has been located, it should not be necessary to remove it.

While the holding device which is shown in FIGURES 1 and 2 is a preferred embodiment of this aspect of the invention, since the holding device can be formed integral with a spring finger 24 used for securing the lamp socket to a tree branch or the like, spring finger 24 actually forming the head of the holding device, it will be appreciated that in less preferred embodiments of this aspect of the invention the head of strip 22 may take a different form. For example, in FIGURE 3 there is no spring finger 24 associated with holding device 21, spring finger 24 being replaced by a more conventional head 311 in the form of part of a sphere, head bearing against part 11 of the housing adjacent opening 19. Apart from this change, however, holding device 21 of FIGURE 3 is the same as holding device 21 shown in FIGURE 2.

Another aspect of this invention is illustrated in detail in FIGURE 4. Turning to this figure, there are shown

electrical contacts

13 and 14. Each of these contacts comprises a strip 13a and 140 respectively of electrically conductive material each bent upon themselves at one end to formgenerally hook-

shaped ends

13b and 14b respectively. Each of hook-shaped ends 1311 and 14b carry an electrically conductive insulation-

piercing pin

17 and 18 respectively, these pins being formed integral with

strips

13a and 14a and being bent at approximately right angles to the planes of

strips

13a and 14a. Pin 18 is positioned closer to its hook-shaped end 14b than is pin 17 positioned relative to its hook-shaped end 1317, so that when

contacts

13 and 14 are positioned side-by-side in gripping engagement with insulated

electrical conductors

15 and 16, as best shown at the bottom of FIGURE 4,

pins

17 and 18 are oifset with respect to each other, and each pierces a different one of insulated conductors l5 and 16. However, it will be noted that both of

contacts

13 and 14

grip conductors

15 and 16 and hold them in place.

'One end 140 of contact 14 is bent in the same plane as and over hook-shaped end 14b. Both

contacts

13 and 14 have

fingers

31 and 32 respectively projecting therefrom intermediate the ends thereof.

Fingers

31 and 32 point towards each other when

electrical contacts

13 and 14 are mounted on insulated

electrical conductors

15 and 16, as best shown in the lower part of FIGURE 4.

As most readily seen in FIGURES 4 and 7, insulated

electrical conductors

15 and 16 are mounted one on top of the other in hook-shaped ends 1311 and 14b, with both conductors being gripped and held in position by both hook-shaped ends. However, pin 17 electrically contacts the wire in insulated conductor 15, while pin 18 electrically contacts the wire in insulated conductor 16.

It is important to note that both

electrical contacts

13 and 14 are mounted on

insulated conductors

15 and 16 from the same side thereof. This is of considerable importance in facilitating the assembly of the electrical contacts on the insulated conductors.

Because of the nature of

electrical contacts

13 and 14, they can readily be made from a single strip of conductive material which is shown in FIGURE 4 at 33. This strip of material has spaced-apart openings 34 therein. In the manufacture of

contacts

13 and 14, strip 33 is severed along line 35 so that the cut-off part 36 is of generally H-configuration. In a

subsequent operation pins

17 and 18 and part 140 are bent downwardly, and at the same time,

fingers

31 and 32 are severed along a line therebetween to form the separate

electrical contacts

13 and 14. These contacts then may be mounted on

insulated conductors

15 and 16 by bending

ends

13b and 14b over the conductors, which causes

pins

17 and 18 to pierce the insulation of insulated

conductors

15 and 16 and causes both contacts to grip both insulated

conductors

15 and 16.

Because of the particular configuration of

electrical contacts

13 and 14, they can both be made from a single strip of material by simple bending and cutting operations, and they can readily be assembled on insulated

conductors

15 and 16, because of the fact that they are mounted on one side rather than on both sides of

insulated conductors

15 and 16. It will be seen that the nature of

electrical contacts

13 and 14 permits ready assembly of sets of these contacts in spaced-apart relationship upon

insulated conductors

15 and 16, as is required in the provision of a Christmas tree lighting set, for example. All that is necessary is that

conductors

15 and 16 be advanced to a work station where the electrical contacts are mounted on the conductors, and the conductors then be further advanced so as to bring other portions thereof to the work station for repeating of the previous operation.

A third aspect of this invention is best illustrated in FIGURES 2, 5, 6 and 7. Referring to these figures, it will be seen that

parts

11 and 12 of the housing have a threaded opening 37 formed therein which is adapted to receive the base of a light bulb 38 (shown in ghost outlines in FIGURE 1). It will be seen that one half of opening 37 is formed in each of

parts

11 and 12.

Part 11 of the housing of lamp socket 10 has two

die members

39 and 40 molded therein and positioned below the part of opening 37 provided in housing part 11. Die member 40 is positioned beneath die member 39. Die member 39 has

sides

41 and 42 which are inclined with respect to each other at approximately right angles, these

sides

41 and 42 being separated by a flat surface 43 through which opening 19 extends and a projecting lip 44 having a flat upper surface 45 and an inclined side surface 46. The top surface 47 of die member 39 is fiat and forms the base of opening 37.

Die member 40 is set in a channel 48 which extends part way through part 11 of the housing. Die member 40 has sides 49 which are inclined with respect to each other at an angle slightly less than 90 and which terminate in an upwardly projecting lip 50. Recesses 51 are provided in the side walls of part 11.

Part 12 of the housing is provided with longitudinally extending keys 52 which engage in recesses 51 when

parts

11 and 12 are placed together, so as to prevent relative sliding movement between

parts

11 and 12. Part 12 has a cavity 53 which is adapted to receive die

members

39 and 40. Connecting with cavity 53 is a channel 54 which coacts with channel 48 to provide an opening through which

conductors

15 and 16 may enter the housing of the lamp socket, this opening being designated 55 in FIGURES 1 and 2. Also, as best shown in FIGURE 6, a channel 56 is provided in part 12 in the threaded part of Opening 37.

As best seen in FIGURES 1 and 2, a recess 57 is provided in part 11 with spring finger 24 extending over recess 57.

In order to assemble a lamp socket embodying this invention, the electrical contact assembly shown in the bottom part of FIGURE 4 is laid in part 11 of the hous ing with the parts of insulated conductors'lS and 16 between

contacts

13 and 14 lying across lip 50 of die member 40, and with

fingers

31 and 32 lying on flat surface 45. Part 12 then is positioned over part 11 in the manner shown in FIGURE 7 and is pressed towards part 11. This action causes

insulated conductors

15 and 16 to be bent over die member 40, as best shown in FIG- URE 7. This action additionally causes

electrical contacts

13 and 14 to spread apart, both contacts eachbeing moved through an angle of about so that bent part 14c turns across surface 47 and extends to the centre thereof, while the corresponding end of contact 13 positlons itself in channel 56 and extends into opening 37. This is the position of

contacts

13 and 14 shown in FIG- URE 7, where it also will be noted that

fingers

31 and 32 lie against

surfaces

42 and 41 respectively, as do

strips

13a and 14a. Edges 39a of die member 39 serve as stops for

electrical contacts

13 and 14.

A lamp socket made from

parts

11 and 12 of the housing shown in FIGURES 5 and 6 is intended as a series socket, in view of the fact that opening 55 does not extend completely through the socket. In such a series socket conductors and 16 are out within the socket, as shown in solid outlines in FIGURE 7. If it is intended, however, that lamp sockets be connected in parallel, the socket illustrated is merely modified by continuing

channels

54 and 48 completely through both

parts

11 and 12 of the housing, so that

conductors

15 and 16 may pass completely through the housing, as shown in dotted lines in FIGURE 7.

After the parts of the housing have been assembled in the aforementioned manner, holding device 21 is placed in the position shown in FIGURE 2, whereupon a com plete lamp socket is formed.

An important feature of the construction of a lamp socket embodying this invention is that it can be readily assembled without the necessity of separately inserting contacts in recesses provided in the housing part of the socket, and the sockets lend themselves to ready assembly on conductors bearing a plurality of spaced apart sets of

electrical contacts

13 and 14, as is the case with Christmas tree light sets, for example. A further important feature is the fact that all but part 140 of the electrical contacts are carried in part 12 of the housing of lamp socket 10, thus permitting the provision of recess 57 to accommodate a tree branch or the like, so as to enable the socket to be more closely centred on the tree branch without having to extend the length of the socket. Another important feature of such a socket is that it can be used for series or parallel wiring without modification of the contact arrangement and without modification of

housing parts

11 and 12, except, of course, that a socket for parallel wiring requires an opening 55 extending completely therethrough, whereas a socket for series wiring does not necessarily.

While there has been disclosed herein preferred ernbodiments of this invention, those skilled in the art will appreciate that changes and modifications may be made therein without departing from the spirit and scope of this invention as defined in the appended claims.

What I claim as my invention is:

1. A lamp socket comprising a housing formed in at least two parts, electrical contacts, said electrical contacts being positioned in said housing, a first spring finger mounted on said housing, a member formed integral with Said first spring finger, partially cut-away therefrom and bent away from said first spring finger, said member carrying a generally hook-shaped second spring finger remote from said first spring finger, a first One of said parts of said housing having a first opening extending therethrough, a second one of said parts of said housing having a second opening extending only part way therethrough and defined by side walls, said member extending through said first opening, said second spring finger being inserted in said second opening and being in a flexed position in said second opening, a part of said second spring finger bearing against one of said side walls of said second openg, whereby withdrawal of said member from said housing is resisted, said first spring finger bearing against said first part of said housing, said member in conjunction with said first spring finger holding said parts of said housing together.

2. A lamp socket according to claim 1 wherein there is a recess formed in said first part of said housing, said first spring finger extending over said recess and cooperating therewith to provide means for mounting said socket on a branch or the like.

3. Means for conducting electrical energy to a lamp socket comprising a plurality of insulated electrical conductors and a set of electrical contacts, each contact of said set of contacts comprising a strip of electrically conductive material bent upon itself at one end to form a generally hook-shaped end, said hook-shaped end carrying an electrically conductive insulation-piercing pin, one of said pins being positioned closer to its hook-shaped end than the other of said pins, whereby when said contacts are positioned side-by-side in gripping engagement with said insulated electrical conductors said pins are offset with respect to each other, the end of one of said contacts remote from said hook-shaped end thereof being bent in the same plane as and over said hook-shaped end thereof, said insulated electrical conductors being mounted one on top of the other in said hook-shaped ends and all being gripped and held in position by said hook-shaped ends, said electrical contacts both being mounted on said insulated electrical conductors from the same side thereof, said pins piercing the insulation of different ones of said insulated electrical conductors and electrically contacting different ones of said conductors.

4. The invention according to claim 3 wherein each of said strips of material has a finger projecting therefrom intermediate the ends of said strip of material, said fingers pointing towards each other when said electrical contacts are mounted on said insulated electrical conductors.

'5. The invention according to claim 3 wherein said insulated electrical conductors are bent between said electrical contacts.

6. A lamp socket comprising a housing formed in two parts, a plurality of electrical contacts, said electrical contacts being positioned in said housing, and means for holding said parts of said housing together, said socket having an opening therein adapted to receive the base of a light bulb, a part of said opening being formed in both of said parts of said housing, one of said parts of said housing having first and second die members positioned below the part of said opening formed in said one part of said housing with said second die member beneath said first die member, said first die member having sides angularly inclined towards each other, said die members projecting into a cavity in said other part of said housing beneath said part of said opening formed in said other part of said housing, and electrical conductors passing into said housing, said electrical contacts electrically contacting diiferent ones of said electrical conductors and being in spaced-apart relationship with respect to each other, the portion of said electrical conductors between said electrical contacts being bent over said second die member, one of said electrical contacts resting against one of said angularly inclined sides of said first die member, the other of said electrical contacts resting against the other of said angularly inclined sides of said first die member.

7. A lamp socket according to claim 6 wherein said sides of said first die member are at an angle of about to each other.

8. A lamp socket according to claim 6 including a recess formed in said one part of said housing and adapted to accommodate the branch of a tree or the like.

9. A lamp socket according to claim 6 wherein said first die member has an upper surface, said upper surface forming the bottom of said opening, one of said electrical contacts having a bent-over portion lying across said upper surface, said other part of said housing having an open channel therein extending along the side wall defining said part of said opening in said other part of said housing, a part of the other of said electrical contacts lying in said channel.

-10. A lamp socket according to claim 6 wherein said one part of said housing has a first opening extending therethrough, said other part of said housing has a second opening therein defined by second side walls, said holding means comprising a member having a head and carrying a spring finger projecting sideways from said member and positioned remote from said head, said member extending through said first opening, said spring finger being inserted in said second opening and being in a flexed position in said second opening, a part of said spring finger bearing against one of said second side walls of said second opening, whereby withdrawal of said holding means from said housing is resisted, said spring finger in conjunction with said member holding said parts of said housing together.

11. A lamp socket according to claim 10 wherein said head comprises a spring finger.

12. A lamp socket according to claim 11 wherein there is a recess formed in said one part of said housing, said last-mentioned spring finger extending over said recess and co-operating therewith to provide means for mounting said socket on a branch or the like, said last-mentioned spring finger being formed integral with said member.

13. A l-amp socket according to claim 6 wherein said electrical conductors are insulated, each of said contacts comprising a strip of electrically conductive material bent upon itself at one end to form a generally hook-shaped end, said hook-shaped end carrying an electrically conductive insulation-piercing pin, one of said pins being positioned closer to its hooked-shaped end than the other of said pins, whereby when said contacts are positioned side-by-side in gripping engagement with said insulated electrical conductors said pins are ofiset with respect to each other, the end of one of said contacts remote from said hook-shaped end thereof being bent in the same plane 'as and over said hook-shaped end thereof, said insulated electrical conductors being mounted one on top of the other in said hook-shaped ends and all being gripped and held in position by said hook-shaped ends, said electrical contacts both being mounted on said insulated electrical conductors from the same side thereof, said pins piercing the insulation of different ones of said insulated electrical conductors and electrically contacting ditferent ones of said conductors.

14. A lamp socket according to claim 13 wherein each of said strips of material has a finger projecting therefrom intermediate the ends of said strip of material, said fingers each resting against a different one of said inclined sides of said first die member.

15. A lamp socket according to claim 13 wherein said one part of said housing has a first opening extending therethrough, said other part of said housing has a second opening therein defined by second side walls, said holding means comprising a member having a head and carrying a spring finger projecting sideways from said member and positioned remote from said head, said member extending through said first opening, said spring finger being inserted in said second opening and being in a flexed position in said second opening, a part of said spring finger bearing against one of said second side walls of said second opening, whereby withdrawal of said holding means from said housing is resisted, said spring finger in conjunction with said member holding said parts of said housing together.

References Cited by the Examiner UNITED STATES PATENTS 1,818,884 8/31 Eckstein 339-99 2,704,832 3/55 Greenbaum 339l 57 X 3,127,229 3/64 Beck 33999 3,151,926 10/64 Schick et al. 339-99 JOSEPH D. SEERS, Primary Examiner.

W. DONALD MILLER, Examiner.

Claims

1. A LAMP SOCKET COMPRISING A HOUSING FORMED IN AT LEAST TWO PARTS, ELECTRICAL CONTACTS, SAID ELECTRICAL CONTACTS BEING POSITIONED IN SAID HOUSING, A FIRST SPRING FINGER MOUNTED ON SAID HOUSING, A MEMBER FORMED INTEGRAL WITH SAID FIRST SPRING FINGER, PARTIALLY CUT-AWAY THEREFROM AND BENT AWAY FROM SAID FIRST SPRING FINGER, SAID MEMBER CARRYING A GENERALLY HOOK-SHAPED SECOND SPRING FINGER REMOTE FROM SAID FIRST SPRING FINGER, A FIRST ONE OF SAID PARTS OF SAID HOUSING HAVING A FIRST OPENING EXTENDING THERETHROUGH, A SECOND ONE OF SAID PARTS OF SAIDHOUSING HAVING A SECOND OPENING EXTENDING ONLY PART WAY THERETHROUGH AND DEFINED BY SIDE WALLS, SAID MEMBER EXTENDING THROUGH SAID FIRST OPENING, SAID SECOND SPRING FINGER BEING INSERTED IN SAID SECOND OPENING AND BEING IN A FLEXED POSITION IN SAID SECOND OPENING, A PART OF SAID SECOND SPRING FINGER BEARING AGAINST ONE OF SAID SIDE WALLS OF SAID SECOND OPENING, WHEREBY WITHDRAWAL OF SAID MEMBER FROM SAID HOUSING IS RESISTED, SAID FIRST SPRING FINGER BEARING AGAINST SAID FIRST PART OF SAID HOUSING, SAID MEMBER IN CONJUNCTION WITH SAID FIRST SPRING FINGER HOLDING SAID PARTS OF SAID HOUSING TOGETHER.