US2525577A - Safety socket and switch assembly for electric light bulbs and the like - Google Patents

Description

. T, n. A. ANDERS N SAFETY SOCKET AND SWITCH cAssEMBLY FCR ELECTRIC LICHT BULBS AND THE LIKE 2 Sheets-Sheet 1 Filed Sept. 23, 1947 INVENTOR.

R. A. ANDERSON SAFETY SOCKET AND SWITCH ASSEMBLY FOR ct.. 1950 2,525,577 Y ELECTRIC LIGHT BULBS AND THE LIKE 2 Sheets-Sheet 2 Filed Sept. 23, 1947 Patented Oct. 10, 1950 SAFETY SOCKET AND SWITCH ASSEMBLY FOR ELECTRIC LIGHT BULBS AND THE LIKE Ralph A. Anderson, Evanston, Ill., assigner to Nicholas J.` Zaro, New York, N. Y.

Applicationseptember 23, 1947, Serial No. 775,725

Claims. l This invention relates to a safety'socket and switch assembly for electric light bulbs and the like, and more particularly to such structure having increased safety against anyone receiving a shock when they insert a nger or a metallic in-` strument into the socket when the bulb is not screwed therein.

The present invention is an improvement over that disclosed in my eopending application Serial No. '707,694 led November 4, 1946, now forfeited, for Safety Socket for Electric Light Bulbs and the Like. In said oo-pending application provision was made for preventing a shock being received from inserting a nger or other projection into the screw shell. In the present invention this assurance against receiving such shock is further greatly increased by the provision of a switch assembly so constructed in connection with the safety socket that' no electric current can flow into the center contact in the body waferuntil after the lightbulb is screwed into the screw shell, and even then not until the switch is closed.

Among theobjects of my invention are: to provide a novel and improved safety socket and switch assembly for electric light bulbs and the like; to provide a safety socket and switch assembly capable of passing electric current to both the screw shell and the center contact of the body wafer only when a bulb is screwed into the shell and the switch is closed; to provide a safety socket and switch assembly having a` screw shell, a pair of wafers, a bracket, and switch operating7 mechanism mounted in the bracket; to provide a safety socket having double safety features against shock; to provide a safety socket and switch assembly having switch contacts that do not contact after the switch is moved' to closing position, until a bulb is screwed into the shell; to provide a novel switch and switch operating means for a safety socket; to provide a safety socket and switch assembly mounted in a housing as a floating unit; and such further objects, advantages and capabilities inherently possessed by my invention, as will later more fully appear,

My invention further resides in th-e combination, construction and arrangement of parts illustrated in the accompanying drawings, and while I have shown therein for illustrative purposes a preferred embodiment, I wish it understood that the same is susceptible of modification and change without departing from the spirit of my invention. Y

In the drawings:

Fig. 1 is a longitudinal section taken on a median plane, of a safety socket and switch assembly embodying my invention.

Fig. 2 is a top plan view of Fig. l.

Fig. 3 is a view similar to Fig. l, but showing the device as being rotated through degrees on its longitudinal axis.

Fig. 4 is a transverse section on the line -d of Fig. 1.

Fig. 5 is a side elevation of my device but showing a light bulb plug screwed into the shell, the shell in longitudinal section, the outer housing partly broken away and the switch closed.

Fig. 6 is a view similar to Fig. 5 but rotated through 90 degrees on the longitudinal axis, and showingthe bottomportion of the switch assembly in section.

Fig. 7 is a perspective view of bracket.

Fig. 8 is a perspective View of the annular bowed spring for normally urging the two wafers away from each other.

In the form shown for illustrative purposes in the drawings, my improved safety socket and switch assembly comprises an outer metallic casing or housing I having an increased diameter in its lower portion as viewed in Fig. l, the lower marginal edge of which receives a cover member 2 having xed axially therein a. neck 3 having a central opening 4 preferably formed with screw threads. This housing may be, if desired, a conventional housing such as used in electrical` iixtures. Positioned inside of housing I is a shell insulating liner 5 which may be formed of paper or other suitable` insulating material. Approximately midway of their length the liner 5' and the housing I are outwardly curved at 6 and I to form` a somewhat larger diameter in the lower half thereof.

Inside of the insulating liner 5 is a tubular metallic screw shell 8 formed with threads 9 for threadably receiving the plugr II) of a light bulb II. Shell 8` at two opposite sides of its bottom end is formed with inwardly extending flanges I2 and I3 fixed by rivets I4 and I5 to the insulating body wafer I6. Also fixed between the upper head of each of these rivets and the adjacent shell flange is a metallic, annular, bowed spring member I'I which` at its opposite sides is formed with the upwardly extending bowed portions I8 and I9, the uppermost portions of which bowed portions are formed with downwardly extending curved bent portionsZil and '2L Openings 22` are the supporting formed in spring member I'I at diametricallyop;l` Dosite points for receiving the metallic rivets It' and 5.-.

Insulating body wafer |6 is formed at opposite sides of its center with slots 23 and 24 for slidably receiving the upstanding arms 25 and 26 of a bracket supporting member 21. Fixed upon the upper ends of bracket arms 25 and 23 is a top insulating wafer 28 which is provided in its central portion with a center metallic contact 29. The means for nxing the top wafer 28 to bracket arms 25 and 26 are shown in Fig. 5 and may comprise staking means formed by chisel indentations 36, or any other suitable means to hx said top wafer against movement longitudinally of the bracket arms. As seen in Figs. l, 3, and 6 the bowed spring l1 is positioned between the body wafer |65 and the top wafer 28 to normally urge these two wafers away from each other, as will be understood in my said copending application. As seen in Figs. 3 and 6 the bracket 21 is so formed that the arms and 26 are bent outwardly somewhat at an angle, and then downwardly and inwardly to form a bottom 3| having a central opening 32 for a purpose later more fully explained. Fixed to the body Wafer i6 is a terminal member 32 secured to the body wafer by a metallic rivet 33 which is, when a bulb is not screwed into the shell, away from contact with the screw shell. Threadably mounted in terminal member 32 is a binding screw 34 to secure the bared. end of a conductor 35 to this terminal member.

Fixed to the body wafer i6 by a lcentral metallic rivet or the like 36 is a switch contact member 31 having a downwardly extending arm 38 which is somewhat angular in position for a purpose later more fully explained. As will be seen in Figs. 1 and 3, rivet 36 is in axial alignment with center contact 25 of the top wafer. Also rivet 33 is in vertical alignment with the depressed portion 2U of the bowed spring |1. It will thus be seen that when a light bulb plug is screwed into the screw shell 3, the screw shell and the bottom wafer |6 wil be pulled upwardly to compress the bowed spring |1 and cause contact between depression 2|l of the bowed spring and rivet 33 and contact between the center contact 29 and the rivet 36. When electric current is supplied to terminal members 32 and 31 by means later more fully explained, current will pass through the light bulb and illuminate the same, as is also described in my said copending application. This construction provides a shock proof socket which prevents the possibility of receiving a shock when the finger or a metallic object is inserted into the shell in the absence of a, light bulb being screwed therein. However, to double the assurance of preventing the reception of any shock I have provided a switch assembly by which it is impossible to electrically energize the switch contact arm 38 and the rivet 36 until a bulb is screwed into the shell. When the switch is open it will be obvious that electric current cannot pass to switch contact arm 38, and when the switch is moved to closing position there will be a gap between the switch arm 51 and the switch contact arm 38, which gap cannot be closed until a light bulb is screwed into the shell as will be now described in detail.

Each of the outwardly extending portions of bracket arms 25 and 26 are formed with key slots 39- and 45 each of which have enlarged curved portions 4| and 42 to rotatably receive a rotor shaft 43 which after being passed therethrough is formed at its free end with an upset end 54 to prevent the shaft being inadvertently pulled out of the bracket. Fixed to the opposite end of shaft 43 is a handle member 45 for manually rotating the shaft. Shaft 43 at a suitable intermediate portion of its length is swaged or otherwise upset to provide radially extending ribs 46 and 41. The extensions of the keyhole slots 39 and 4D enable insertion of ribs 46 and 41 through these holes during assembly of the parts. Mounted yupon shaft 43, to have limited oscillation thereon, is a rotor 48 which is formed in one side face with a depression 49 of somewhat greater width than the thickness of the ribs 46 and 41 to permit the rotor to move a slight distance with relation to the shaft to give a snap action when opening the switch. After the rotor has been f slipped over the shaft 43 into proper position with relation to ribs 46 and 41 the same is secured against longitudinal movement by staking or the like as shown at 55 in Fig. 3. Any other suitable fastening means may be used in this connection as desired. The rotor has a slight rotational movement on the shaft limited by the ribs 46 and 41 and the depression 49.

Seated on the bottom inner face of the bracket 21 is an insulating member 5| having a depending circular lug 52 extending into the hole 32 of the bracket. Positioned against the under face of the bottom of the bracket is an insulating washer 53 and seated against the upper face of insulating member 5| is the lower leg 54 of a metallic center terminal member 55 having a lug 55 pressed therefrom to be seated in a recess 51 in member 5| for positioning purposes, lug 56 `resting against the adjacent edge of member 5|. Seated against the upper surface of leg 54 of center terminal 55, is the bottom leg 58 of a switch spring 59. The free end of leg 58 is bent downwardly at 69 to seat in the aperture in leg 54 from which lug 56 was pressed. Passing through washer 53, bottom 3| of the bracket, insulating member 5|, leg 54 of the center terminal 55, and leg 58 of the switch spring 59, is a metallic rivet 6| which is riveted over at its ends to hold these parts iirmly together. As seen in Fig. 1 insulating member 5| is formed on each side of the rivet with a transverse recess 62 to seat over the adjacent portions of the bottom of the bracket. Member 5| is also provided on its edge opposite to that having the recess 51 with a corresponding recess.

Center terminal member 55 has an upstandng portion 63 within which is threaded a binding screw 64 to secure to the upper end of this member the bared end of a conductor 65, which together with conductor 35 are insulated and pass through the insulation of the cord 66, which in turn passes downwardly through the opening 4 in neck 3 to any suitable source of electric cur rent. Switch spring 59 is bent backwardly over the bottom leg 53 to the right as seen in Fig. 1, and then extends upwardly to form a spring arm 61 which forms the movable active arm of this part of the switch. As seen in Fig. 1 switch spring 59 with its switch arm 61 is so bent as to cause arm 61 to always resiliently bear against the marginal edge of rotor 48. The rotor as seen in Figs. 1 and 5 is formed at its ends with two high portions 68 and 69 and at its side edges with two low portions 10 and 1|, whereby when the rotor is rotated from the position shown in Fig. l to the position shown in dotted lines in Fig. 5 the switch arm 61 will be moved to the dotted line position shown in Fig. 1 when a light bulb is not screwed into the shell, which is also the solid line shown in Fig. 5 when a light bulb is screwed into the shell. 'I

As seenin Figs. land 5 each of theends of the high points of the rotor `are formed with a depression to insure that when the switch1is closed the rotor will not be inadvertently.` moved away from switch closing position, except by rotation of shaft 43 through handle 45 by the operator. When the handle l5 is rotated to move the rotor from the position shown in dotted lines in Fig. 5 to open the switch, the ribs il@ and lil of shaft 43 will push against the leading sides of depressions 49, and as Soon as the rotor high point has passed beyond the effective holding surface of switch arm 61 the pressure of this arm against the rotor will snap the rotor` a distance forwardly in a clockwise direction, as viewed in Fig. l, to give a quick opening of the switch, As will be understood a suitable opening will Ibe `formed in the housingi to permit the handle l5 of the switch to extend thereinto. Also as seen in Fig. 3 the switch spring 59 is formed with a longitudinal slot in that portion `just above the lower arm 5s to permit access to the rivet 6l during assembling. In operation the rotor 43 rotates in a clockwise direction as viewed in Fig. l, s that in closing the switch the rotor will rst contact the upper end of switch arm 6l as it begins bending the same, which insures a softer action with less torque than would be the case if the rotor and shaft i3 were rotated in a counterclockwise direction.

The bracket, switch, screw shell, wafers, and associatedl parts are connected together as a floating unit within the housing l. At times when the bulb being inserted is rst introduced into the screw shell the bottom of the bracket and associated parts may be pressed downwardly and contact the insulated wires 35 and 65, and at times during screwing of the bulb into the shell and later the assembled unit may be up away from said insulated wires. In other words it is not necessary that this unit be rigidly fastened to the housing but the saine may move therein as required and at all times the top wafer 28 will be rigidly connected to the bracket and incapable of movement longitudinally therealong by reason of the lower face of the top wafer 23 Vbearing against the shoulders l2, 13, 'i4 and l5 formed on the bracket, which when the top ends of these arms are staked against the top wafer rigidly holds the` top wafer against movement on the bracket. The bottom or body wafer l@ loosely rests against the shoulders 16, this and l of the bracket and is loosely slidable longitudinally of the bracket; when the bowed spring is compressed by screwing a bulb into the shell.

Assuming a bulb to be Screwed into the shell and the switch closed, current will flow through conductor 55, centel1 terminal 55, switch spring 59, switch arm Bl, switch contact 3l, center rivet 35, center contact 29, through the filament in the bulb, thence through the screw shell 8, bowed spring il, rivet 33, shell terminal 32 and conductor 35, thus completing the circuit through the bulb, shell and switch assembly. When, however, a light bulb is not screwed into the shell the bowed spring il will hold the two wafers apart, which of itself would prevent a, shock being received in the socket. However, to further augment safety against receiving `a shock when a bulb is not screwed into the shell, the spring switch 59, and switch` arm @l together with the rotor 43 are so formed and proportioned that when the rotor is rotated into the dotted line position shown in Fig. 5, switch arm 6l will not contact the" switch contact arm 38 but will be spaced a slight distance therefrom as shown in dotted lines in Fig. l. This will further insure againstthe passage of electric current to the switch Contact and the center rivet 3-6 when a light bulb is not screwed into the shell. When a light bulb is screwed into the shell, the switch may be closed to illuminate the bulb or opened to darken the bulb as desired.

As the possibility of anyone receiving a shock by inserting their finger or some metallic object into the shell would be possibleonly when a bulb was not screwed into the shell, it -will be seen that I have provided a double safety means in this regard consisting of, rst, the inability to push the top wafer 28 downwardly as the same is rigidly fixed to the bracket, and the inability to move the shell upwardly to close the contacts in the wafers because of the bowed spring I1, and second, because of the space between the switch arm 6l and the switch contact arm 38 which cannot be closed until a bulb isscrewed into the shell to raise the body wafer and correspondingly move the arm 33 of the switch contact 3l into contact with the movable switch arm 6l. rIhe diameter of the bodyV wafer is suliciently large to prevent pulling the assembly out of the top of thehcusing because of its being stopped by the circumferential bulges 6 and l' of the lining and the housing.

Having described, my invention, I claimf 1. A safety socket `and switch assembly for electric light bulbs and the like, comprising, an outer casing, a metallic screw shell longitudinally movable in said outer casing and adapted to have a light bulb screwed thereinto, an insulating body wafer fixed to said shell, a metallic bracket on which said body wafer is slidably mounted, said bracket having a pair of upstanding spaced apart arms, a topiwafer Xed to said bracket arfns within the shell, contact members in said wafers, spring means between the wafers to normally hold the wafers apart until a light bulb plug is screwed into the shell, a key socket switch contact fixed tosaid body wafer in contact with one of the Contact members in the body wafer, a switch shaft rotatably mounted in said bracket andextending through said arms, a.

vrotor on said shaft betweenisaid arms and having a high point anda low point, a switch spring connected to said bracket and having an arm normally in `contact with the low` point of the rotor, said spring arm being movable toward the key socket switch contact when the rotor is rotated. i

2. A safety socket and switch assembly as claimed in claim l, in which the switch spring arm when the high point of the rotor forces the spring arm to its outermost position is spaced a slight distance from the key socket switch contact until a light bulb is screwed into the screw shell.

3. A safety socket and switch assembly as claimed in claim 2, in which the body wafer and its key socket switch contact move longitudinally of the bracket when a light bulb is screwed into the shell and close the gap between the key socket switch contact and the switch spring arm when the latter stands distended by the rotor. 4. A safety socket and switch assembly as claimed inclaim 3, in which the key socket switch contact projects angularly from the body wafer, and the switch spring arm when distended by the rotor stands at an angle and substantially pal'- 7 allel with the projecting end of the key socket switch contact.

5. A safety socket and switch assembly for electric light bulbs and the like, comprising, a metallic screw shell having a body wafer fixed thereto, a bracket member on which said body Wafer is slidable, a top Wafer xed to said bracket member` within the shell, contact members in said wafers, resilient means between said wafers for normally urging themv apart whereby when a light bulb plug is screwed into the shell theplug will contact a contact member in the top wafer and move the body wafer toward the top wafer to connect a circuit through the bulb, a switch :contact carried by the body wafer, and switch ioperating means mounted on the bracket inemlber and having a movable switch arm which when distended will contact said switch contact to complete the circuit through the bulb only when a bulb is screwed into the shell.

6. A safety socket and switch assembly as Iclaimed in claim 5, in which said switch oper- :ating means includes a rotor shaft rotatably :mounted in the bracket member, and a rotor for moving said switch arm when said shaft is rotated.

7. A safety socket and switch assembly as claimed in claim 6, in which the switch contact jprojects from the body wafer at an angle, and Athe switch arm when distended stands in a position slightly spaced from the switch contact whereby when a light bulb is screwed into the :shell the shell and body wafer will be moved with relation to the bracket member to close :said space.

8. A safety socket and switch assembly, com- I 'jprising, a screw shell having an insulating wafer :fixed thereto, a bracket on which said wafer is slidable, said bracket having an insulating wafer fixed thereto within the shell, contacts in said wafers, means for normally urging said wafers away from each other whereby when a bulb is screwed into the shell the wafer contacts will meet, switch means mounted on the bracket for closing switch contacts only when a bulb is screwed into the shell, said bracket having a pair of spaced apart arms, said first mentioned wafer having openings through which said arms extend, and said switch means including a rotor mounted between said arms.

9. A safety socket and switch assembly for electric light bulbs and the like, comprising, an outer housing, a screw shell and bracket unit loosely mounted in said housing and having means to prevent them from being entirely removed from the housing except when the parts of the housing are separated, a body wafer fixed to the shell, a top wafer fixed to the bracket within the shell, said body wafer being slidable on the bracket, an annular bowed spring between the two wafers normally urging them apart, contacts in the wafers, a switch contact on the body wafer, a shaft and rotor rotatably mounted on the bracket, a spring arm mounted on the bracket resiliently contacting the rotor at all times, said rotor having a cam surface which when the rotor is rotated to move the spring arm to its outermost position adjacent the switch contact but spaced therefrom, said switch contact being movable with the body wafer when a bulb is screwed into the shell to move the switch contact into engagement with the spring arm to complete the circuit through the bulb when the spring arm is in said outermost position.

10.. A safety socket and switch assembly for electric light bulbs and the like, comprising, a metal screw shell having an insulating body wafer fixed thereto, a metal bracket having a pair of laterally spaced apart arms, an insulating top wafer Xed to the top portion of said arms above the bodywafer, said arms passing through the body wafer so that the body wafer is slidable thereon, spring means between said wafers for normally urging them apart, contact members in said wafers, an angularly positioned switch contact on said body wafer eX- tending from the side away from the top wafer, a movable member on said bracket movable to a position close to but slightly spaced from the switch contact, and means for selectively moving said movable member, whereby when the movable member is in said position the screwing of a bulb into the screw shell will move the switch contact upwardly into contact with said movable member.

RALPH A. ANDERSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 881,297 Burton Mar. 10, 1908 1,245,305 Anderson Nov. 6, 1917 1,320,196 Benjamin Oct. 28, 1919 1,951,981 Johnson et al. Mar. 20, 1934 2,158,884 Mueller Mayv 16, 1939 2,268,061 Richards Dec. 30, 1941 2,439,385 Goldberg Apr- 13, 1948

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