US2113218A - Switch - Google Patents

Description

April 5, 1938. k. NIELSEN SWITCH Filed Aug. 3, 1956 2 Sheets-Sheet 1 Patented Apr. 5, 1938 UNITED STATES PATENT CFFICE SWITCH poration of Illinois Application August 3 3 Claims.

The invention relates to improvements in electrical switches, and more particularly to an improved electrical switch having a series of switching contacts adapted to be opened and closed in succession with snap action.

The primary object of the invention is to provide an improved switch of the above general character arranged for reversible operation whereby the series of switch contacts may be operated in either forward or backward progression.

Another object is to provide an improved reversibly operable multiple contact switch of extremely compact form which can` be readily incorporated in standard electrical xtures or appliances, which is adapted to operate efficiently and reliably over a long period of use, and which by reason of the simple construction and advantageous arrangement of the Various parts,

may be manufactured at a relatively low cost.

Other objects and advantages cf the invention will become apparent from the following detailed description of the preferred embodiment illustrated in the accompanying drawings in which:

Figure 1 is a phantom perspective view of the improved switch incorporated in an electric light socket.

Fig. 2 is a vertical sectional view of the switch and socket shown in Fig. 1.

Fig. 3 is a sectional View taken along the line 3 3 of Fig. 2.

Figs. 4, 5, 6 and 7 are elevational views of the switching contacts with the contact operating member shown in its four different positions.

Fig. 8 is a perspective view of the switch mechanism with a portion broken away to show the manner in which the various parts cooperate.

Fig. 9 is a perspective detail view of the switch mechanism showing the parts disassembled.

'Ihe improved switch is particularly adapted for use in electric lighting xtures of the multiple circuit type, although it will be appreciated that it may be employed in other electrical devices and appliances having a plurality of electrical circuits to be opened and closed in succession. By way of illustration the invention is shown incorporated in an electric lamp socket of the type commonly employed for multiple iilament lamps and provides for energizing the filaments independently or together as desired.

The socket in which the improved switch is incorporated in the present instance is of the usual two piece construction including a generally cup shaped lower member I0, (Figs. l, 2 and 3) of -55 porcelain or the like, and an upper member II removably secured thereto, adjacent faces of the members being recessed to provide a suitable compartment I2 for switch mechanism generally designated by reference character I3. Dis- 50 posed within the member Ill is a cylindrical metal 1936, Serial No. 93,950

shell I4 having the walls corrugated in the usual manner i'or engagement with the threaded base of an electric light bulb. The shell I4 constitutes a common terminal for the filaments of the bulb and is electrically connected by means of a screw I5 with a terminal IB to which one of the feed conductors of the electrical supply circuit may be connected. As herein shown, the upper end of the shell is formed with a transverse slot Il to provide space for the other contact members of the socket. The screw I5 operates to hold the shell I4 and the members Iii and li together.

In the standard double filament lamp, one {dlament is connected to a disk shaped contact element located substantially centrally on the end the hase cf the ylhe other ilament is connected to an annular contact element encircling the first mentioned contact element and insulated therefrom. The socket illustrated is acccrdingiy provided with a pair of complementary contact members for engaging the contact ele'- ments on the base of the bulb. One contact member comprises a leaf spring I8 secured at one end to a terminal post I9 anchored in the inember |10. The other end of the spring I8 is positioned to engage the center contact ci the lamp and is yieldably held contacting position by a compression spring 2li. The other Contact member is in the form of a flat spring 2i having an annular end portion 22 positioned to engage the annular contact element on the base of the lamp. The spring 2| is supported by a terminal post 23.

The switch mechanism I3 is arranged for connecting the contact members I8 and 22 selectively with the other feed conductor of the supply line. As will be seen by reference to Figs. 2, 8 and 9, the switch mechanism comprises a shait 2li extending transversely of the socket and into the compartment I2. The shaft is rotatably supported at its inner end by a bearing 25 clamped between the members it and ii and at its other end by bearing 26 carried by a yoke 2l rigidly mounted in the compartment I2. Loosely mounted on the shaft 24 is a generally cup shaped rotor 28 of Bakelite or other suitable insulating material carrying on its closed end a switch operating member preferably in the form of a metal contacter 2S. The contacter is disposed in a slot formed in the rotor so as to be rigid therewith and is insulated from the shaft 24 and bearing 25 by an` insulating washer 25a.

As will be seen by reference to Fig. the contactor 29 comprises an arcuate plate having three similar contact arms 29a, 29b and 29C extending radially from the axis of the shaft 24 and rotor 28. The contact arms are preferably spaced degrees apart so that between the contacts 29a and 29c there is a vacant space ofr 180 degrees.

Arranged around the periphery of the rotor for engagement with the ends of the contact arms are a series of resilient switch contacts 39, 3| and 32. These switch contacts are spaced apart similarly to the spacing of the contact arms and are stationarily mounted in the switch compartment I2. In the present instance the switch contact 30 is supported on a terminal post 33 connecting with a terminal lug 34 to which the other feed conductor of the supply line is connected. The switch contact 3| is electrically connected with the spring contact |8 by the terminal screw I9, and the switch contact 32 is connected with the spring: contact 2I' by the terminal screw 23. Thus, by rotating the contactor 29 to various positions, the switch contact 30 may be electrically connected with the switch contacts 3| and 32 independently or with both of the latter switch contacts simultaneously.

In the embodiment illustrated, the contactor 29 is adapted to be set in four diiferent positions. Fig. 4 shows the contactor in its iirst or open circuit position. In this position the switch contact 30, to which the feed conductor is connected, is disengaged from the contactor, hence no current is supplied to either of the Contact members.

Rotation of the contactor through a quarter revolution in a counterclockwise direction, as viewed in this figure, advances it to its second position shown in Fig. 5. In this position contact arms 29a and 29c engage the switch contacts 30 and 32 respectively, so that current is supplied to the annular contact spring 22. Another quarter revolution advances the contactor to the third position shown in Fig. 6 wherein the contact arms 29a and 29lo engage the switch contacts 3| and 30 respectively to supply current to the contact member I8. Further quarter revolution of the contactor brings the three contact arms into engagement with the three switch contacts as shown in Fig. '7, so that current is supplied to the con tact members I8 and 2| simultaneously. Rotation of the contactor in the opposite direction connects the switch contacts in reverse order. Thus by rotating the contactor through its various positions the switch contacts may be operated, that is, opened and closed successively in either forward or backward progression.

Rotation of the contactor is effected through the medium of actuating mechanism interposed between the shaft 24 and the rotor 28. To prevent excessive sparking at the contacts, the actuating mechanism is arranged to effect each advancing step of the rotor with a snap action. This is accomplished through the medium of a latch device operating in conjunction with a yieldable driving connection between the shaft and the rotor. The latch device also serves to locate the contacter properly with respect to the switch contacts in the various positions of the switch.

Referring more particularly to Figs 2, 8 and 9, the yieldable driving connection between the shaft 24 and the rotor 28 includes a coiled spring 31 encircling the shaft 24 and having its end portions extending outwardly for a substantial distance. Straddling the spring 31 is a clevis 38 having rectangular apertures 39 in the opposite legs for receiving the shaft 24, the sides of the shaft being flattened to prevent rotation of the clevis relative thereto. The spring 31 and clevis 38 are disposed within the hollow rotor 28 with the projecting ends of the spring lying on opposite sides of the clevis and a shoulder 4U formed on the interior Wall of the rotor. Thus when the shaft 24 is rotated, the clevis is likewise rotated and by reason of its disposition between the ends of the spring, tends to move the spring in the direction of the rotation of the shaft. The spring tends to carry the rotor along in the same direction due to the engagement of the end of the spring with the shoulder 40. It will be apparent that when the rotor is held against movement, the spring 31 is tensioned in response to the rotation of the shaft 24. The tensioning is such that the rotor is quickly advanced in the direction y in which the shaft was rotated as soon as the holding means is disabled.

Suitable latch means is provided for holding the rotor against movement in the initial rotation of the shaft. As herein shown, the latch means comprises a latch member 4| and a latch engaging plate 42 both loosely mounted on the shaft 24. The latch member 4| is prevented from rotating by means of upstanding lugs 43 engaging in slots 44 formed in the legs of the yoke 21 which, as pointed out above, is rigidly supported in the compartment l2. The slots 44 are of suicient length to permit movement of the latch member longitudinally of the shaft between latching and unlatching positions. sion spring 45 encircling the shaft and interposed between the end of the yoke 21 and the latch member 4| operates to urge the latch member into latching position. As will be seen by reference to Figs. 8 and 9, the latch member 4| is provided with four radially projecting lugs 46 constituting latch elements which, in the present instance, are spaced 90 degrees apart.

The latch engaging plate 42 which cooperates with the latch member 4| is non-rotatably se- A comprescured to the rotor 28 by means of radially projecting lugs 41 engaging in slots 48 formed in the walls of the rotor. The plate 42 is provided with a pair of oppositely facing latch engaging lugs 49 and 49a spaced on opposite sides of the axis of the plate. The arrangement is such that the latch engaging lugs coact with diametrically opposite latch elements 46 when the member 4| is in latching position to hold the rotor against movement in either direction in the initial rotation of the shaft,

For disengaging the latch member 4| and the latch plate 42, latch releasing means arranged to become effective after the shaft is rotated through a predetermined angle is provided. In its preferred form, the latch releasing means includes a lifter 50 interposed between the latch member 4| and the latch plate 42. The latch plate is provided with a pair of outwardly projecting cam surfaces 5| disposed adjacent the latch engaging lugs 49, and the lifter 5G is formed with a cam follower 52 adapted to cooperate with the respective cam surfaces when the lifter is rotated in one direction or the other. The lifter is arranged to rotate with the shaft 24 and to this end is formed with a rectangular aperture 53 for receiving the shaft, the flattened sides of the shaft preventing rotation of the lifter relative thereto. When the shaft is rotated through approximately a quarter of a revolution, the cam follower 52 rides up on one or the other of the cams 5|, thereby moving the lifter 50 outwardly from the plate 42 and shifting the latch member 4| to latch releasing position against ie action of the spring 45. During this rotation of the shaft the spring 31 is tensioned as hereinbefore explained so that, upon the release of the latch mechanism, the spring becomes effective to quickly advance the rotor inthe direction in which the shaft was rotated. As the rotor and latch plate catch up with the shaft, the cam follower 52 leaves the cam surface 5I, thereby permitting the spring 45 to return the latch member 4I to latching position so that movement of the rotor is interrupted at the point at which the contactor operatively engages` the switch contacts.

By reason of the two cam surfaces and two latch engaging lugs provided in the present instance, the latch mechanism may be released upon rotation of the shaft 24 in either direction. In each instance the rotor is advanced in a quick step in the direction in which the shaft was rotated responsive to the release of the latch mechanism. Thus, the contactor engages and di.,- engages the switch contacts with a snap action so that sparking of the contacts is substantially reduced or prevented, and the life of the mechanism is thereby materially increased.

Any suitable means may be employed for rotating the shaft 24. As herein shown, this means is in the form of a manual gripping member 54, non-rotatably secured to the shaft and is held in place thereon by a suitable screw 55 threading into the end of the shaft.

The operation of the switch mechanism, briefly is as follows:

Assuming that the switch is in open circuit position, as shown in Fig. 4, current may be supplied to either contact member I8 or 22 by turning the shaft 24 in one direction or the other. Thus, if the shaft is turned in a clockwise direction as viewed in Fig. 8, spring 31 is tensioned and the contactor is moved to the position shown in Fig. when the latch mechanism releases the rotor to the action of the spring. This release is effected by the lifter 50 whose cam follower 52 engages the cam surface 5I and moves the latch member 4I to unlatching position. The contactor may be returned to open circuit position at any time by rotating the shaft in the opposite direction, the reversible operation making it unnecessary to pass through the other switch positions. This reduces wear of the parts and is also advantageous in reducing the current consumption of the lamp or other device controlled by the switch mechanism.

The same cycle of operations ls repeated in the movement of the switch from each position to the next, the latch mechanism delaying movement of the rotor until the spring 31 is tensioned and thereupon permitting the spring to advance the rotor with snap action to the succeeding position.

It will be apparent from the foregoing that the invention provides an improved multi-circuit switch, adapted to open and close: a series of circuits with snap action in either forward or backward progression. The switch is compact in form and may be readily incorporated in standard electrical fixtures or appliances. It is erlicient and reliable in operation and the parts are of simple construction so that it may be manufactured at a relatively low cost.

I claim as my invention:

1. A socket for double filament electric lamps comprising, in combination, a lower shell member having a recess in one end adapted to receive the base of an electric lamp, a pair of contact members in said recess positioned for engagement by the respective filament contacts of the lamp, an upper shell member removably secured to the upper end of said first member, complementary recesses* formed in adjacent ends of said members to provide an enclosed switch compartment for the socket, and a switch mechanism disposed in said compartment operative to close electrical circuits for said contact members successively in either forward or backward progression, said mechanism comprising a shaft having one end projecting from said compartment, a bearing element rigidly clamped between said upper and lower shell members for rotatably supporting said shaft, a contactor loosely mounted on said shaft and operative to open and close the circuits for said contact members, spring means yieldably connecting said contactor with the shaft whereby rotational movement of the shaft in either direction tends to rotate said contactor in the same direction, latch means operatively associated with the contactor cooperating with a latch element stationarily supported by said shell members to prevent rotation of said contactor, and means rendered operative by the rotation of said shaft through a predetermined angle for disengaging said latch means from said latch element, said spring means acting thereupon to rotate said contactor into or out of circuit closing position with a snap action.

2. A socket for a double filament electric lamp having, in combination, a lower shell member formed with a recess in one end adapted to receive the base of an electric lampi, a pair of contact members in said recess positioned for engagement with the respective filament contacts of the lamp, a second recess in the opposite end of said member adapted to receive an electric switch including a first switch contact adapted to be connected to a current supply conductor and second and third switch contacts connected to said contact members respectively, said switch members all being supported on said lower shell member and disposed adjacent said second recess, a movable contactor having an open circuit position and a plurality of circuit closing positions in which connections are established successively between said first switch contact and said second switch contact, between the first switch contact and said third switch contact, and between said first switch contact and the second and third switch contacts simultaneously, said contactor being movable from one position to either adjacent position with a snap action, and an upper shell member adapted to be removably secured to said lower shell member above said second recess to enclose said electric switch and to hold said switch in place in the socket.

3. A. socket for a double filament electric lamp having, in combination, a shell adapted to receive the base of a lamp, a first switch contact adapted to be connected to a current supply conductor, second and third switch contacts for supplying current to the respective lamp filaments, said switch contacts being stationarily mounted on said shell, a contactor rotatably mounted within the shell having an open circuit position and a plurality of circuit closing positions in which connections are established successively between said first contact and said second contact, between said first contact and said third contact and between said first contact and the` KARL K. NIELsEN.

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