US2087071A

US2087071A - Electric switch

Info

Publication number: US2087071A
Application number: US673421A
Authority: US
Inventors: Marcus H Rhodes
Original assignee: MH Rhodes Inc
Current assignee: MH Rhodes Inc
Priority date: 1933-05-29
Filing date: 1933-05-29
Publication date: 1937-07-13
Anticipated expiration: 1954-07-13

Description

my 33 1937a M. H. RHQDES 2,087,071

ELECTRIC SWITCH Filed May 29, 1955 3 Sheets-Sheet l n ik July 13, 193.7o

M. H. RHODES ELECTRIC SWITCH Filed May 29, 1953 5 Sheets-Sheet 2 July 13, 1937. M, M Ln-3015355 LST ELECTRIC SWITCH Filed May 29, 1953 F|G-6 ly 6 WQ?, 6 WWW W Z /0 [y 60 3 Sheets-Sheet l5 l Patented July 13, 1.937

PATENT oFFicE ELECTRIC SWITCH Marcus Il. Rhodes, Hartford, Conn., assignor to M. H. Rhodes, Inc., Hartford, Conn., a corporation of Delaware Application May 29, 193s, serial No. 673,421

` Claims.

This invention relates to electric switches,

and with regard to certain more specic features, -to electric time-controlled switches.

Among the several objects of the invention 5 may be noted the provision of an electric timecontrolled switch which has but one handle for both actuating and setting purposes, said handle beingl arranged to be used consecutively as a switch-actuating handle and then as` a time-set- 10 ting handle; the provision of a switch ofthe class described which makes and breaks contacts with a snapping action, thereby avoiding deleterious arcing and sparking; and the provision of a switch of the class described which is relatively simple in construction and operation, and which is so constructed as to have a minimum number of wearing parts. Other objects will be in part Obvious and in part pointed out hereinafter.,

The invention accordingly comprises the ele- 0 ments and combinations of elements, features of construction, and arrangements ci partsAwhich will be exemplied lin the structures hereinafter described, and the scope of the application of which will be indicated in the following claims. 2,.. In the accompanying drawings, in which are illustrated several of various possible embodiments of the invention,

Fig. 1 is a front elevation of a time-controlled witch embodying the present invention;

Fig. 2 is a back elevation of the switch shown in Fig. 1;

Fig. 3 is a plan of a base forming a part of the switch of Fig. 1;

Fig. 4 is a cross section taken on line 4 4 of Figs. 1 and 3;

Fig. 5 is a view similar to Fig. 3. but illustrating certain parts in alternative operating positions;

Fig. 6 is a view similar to Figs. 3 and 5, but

illustrating still further operating positions;

Fig. 7 is a cross section taken substantially on line 1--1 of Fig. 6;

Fig. 8 is a cross section taken substantially on line 8-8 of Fig. 4; and, f' 4;, Fig. 9 is a perspective view of a latch lever.

Similar reference characters indicate corresponding parts throughout the several views of the drawings.

Referringl now more particularly to Fig. 1, nu-

meral`2 indicates a switch casing, which preferably comprises a molded bakelite or like material box having a front 4 and four sides 6 formed integrally. Through a suitable hole in the front I projects a shaft 23 which comprises the main shaft of the switch. Two opposite corners of the (Cl. 20G-38) box 2 have molded therein fillets I0, which are 4drilled and tapped to receive screws I2. which screws i2 serve to hold a back mounting panel or base H to the box. ,The base I4 (see Figures 4* and v'7) is grooved as at numeral i6 to receive 5 the edges of the sides On the front of the box there is provided a dial B88, and a handle or cooperating indicating .knob Ei is provided on the end of main shaft 23.

A projection @92 molded with the switch housing 10 serves as a stop to prevent rotation of the knob i90 in the wrong direction. Suitable index characters on the dial E88 indicate the particular deiay for which the switch is set at any given instant. A pair of dots 0M and i196 are also pro- 15 vided on the dial @88, the dot l94 indicating the device to have reached the stage indicated by Fig. 5, while the dot H96 indicates that the de-l vice has reached the stage indicated by Fig. (i, as

is more fully pointed out hereinafter. Instruc- 20 tions to the user of the switch should specify that, to operate it, the knob should first be rotated in a clockwise manner past the two dots GSI and |96 (at each of which a click" will be heard), and then set to the desired time delay, either greater or less than that represented by the location of the dots. The switch may be turned oi at any time While it is running by merely manually rotating the knob back to zero setting, and thus replacing the time-controlled 30 running down with an instantaneous manual running down.

The base i4 is likewise formed of molded material, `such as bakelite, and includes a number of projections and the like integrally formed there- 35 with, which projections will be individually indicated as the occasion arises in this description.

Broadly speaking, the time-controlled switch comprises two parts, namely, the mechanical switching mechanism and the time delay mecha- 40 nism, which are interconnected by a series of latches and the like. For clarity, the mechanical switching mechanism will rst be described, and thereafter the time delay mechanism, while the two will be correlated in connection with the de- 45 scription of the operation of the switch as a whole.

The mechanical switching mechanism is mounted entirely upon the base Il. It comprises a pair of terminals I8 and 2D, which are sup- 50 ported on projections 22 and 2l, respectively, molded integrally with the base Il. Each terminal comprises a flat piece of brass having a hexagonal portion 26 which iits into a receiving hexagonal depression in the projections 22 and 55 portion 26 of the terminal.

- ported in base I4 (see Figures 3 and '7).

24, and an outwardly extending, doubly-beveled portion 28. The terminals are 'mounted on the base |4 in the manner illustrated in Fig. 4. An inwardly threaded hollow cylinder 30 is molded permanently into lthe base I4, and extends therethrough. The inner end of the cylinder 30 is upset as at numeral 32 to clamp the hexagonal Into the outer end of the cylinder 30 is threaded a screw 34, which screw 34 comprises the means for making exterior connections to the switch.

Mounted on a pin 36 which is supported in the base I4 (see Figures 3, 4 and 7) is a rotating contactor bar assembly. This assembly comprises a spacing washer 38, a double-blade contactor bar per se 40, which is spaced apart by a second washer 42, a third, spacing washer 44, and an anvil piece 46. The contactor bar 40 has two arms 48 and 50, which extend radially from the pin 36 in such directions that when one engages the terminal I8, the other will be engaging the terminal 20.A The arms of the bar 40 each comprise two spaced blades of spring material, such as copper, brass or bronze, and each blade terminates sidewardly with flared lips 52, so as the better to engage the terminals I8 and 20. The anvil piece 46 preferably comprises ber or similar material, andincludes, on its upper surface, a substantially rectangular notch 54. The spacing washer 42 has an upturned projection 56 which iits into a hole 5'8 in the anvil piece 46, whereby-rotation of the anvil piece 46 relatively to the contactor bar 40 is positively prevented.

It will readily be seen that through rotation of the anvil piece 46, the terminals I8 and 20 may be connected or disconnected at will with the coextensive rotation of the contactor bar 40. The devices thus far described may be characterized as the electrical elements of the mechanicalv switching mechanism.

' The switch operating mechanism issubstantially all mounted upon a pin 60 which is sup- First in order of mounting on the pin 60 is a swingable hammer saddle member 62, which comprises an arm 64, at the upper end of which is a. hole through which the pin 60 passes, a cross piece 66, and a. portion 68 parallel to the arm 64. On the cross piece 66 is a nose 10, the function of which will be indicated hereinafter. The arm 64 is of suitable length such that the cross piece 66 at all times fits within the notch 54 in the anvil piece 46. Swinging of the hammer saddle 62 is limited by a pair of projections 12 molded on the base I4.

The next piece mounted on the pin 60 is a member 14, which comprises a plate 16 which is par-l allel to the axis of the pin 60, but displaced therefrom, and a pair of projections 18 extending at right angles from the plate 16 and drilled to slide v on the pin 60. The plate 'I6 extends some distance upwardly from the projections 18, and at its upper end is drilled to receive one end of a tension spring, the other end of which is anchored to a pin 82 mounted near the edge of base I4. Since the spring always imparts a counterclockwise rotational tendency to the member 14, and since it Ais necessary to limit the rotation of said member 'I4 in that direction, a stop pillar 84 is molded as part of the base I4, against which the lower end of plate 'I6 abuts to limit such rotation. The pillar 84 also serves as a mounting means, as will be pointed out more fully 'hereinafter. On a line with the pin 60, a pair of slots 86 are provided in the projections T8, into which slots slides a plate 88 having a nose 90 at the front end thereof.

Reacting between the nose I0 on the hammer saddle 62 and the nose 90 on the plate 88 (and hence the member 14) is a compression spring 94. The compression spring 94, member 14, and hammer saddle 62 together constitute an over-centering device, as follows: When the member `|4 is rotated clockwise, against the spring 80, and the hammer saddle 62 is held stationary by reason of its engagement with the left-hand projection l2 (in other words, when the member 'I4 is rotated clockwise from its position as indicated in Fig. 3), the compression spring 94 is slowly compressed against the nose 10 Von the hammer saddle, until a point is reached where the nose 10, the axis of -it rotates counterclockwise under the force ofv spring 80, and the hammer saddle is swung sharply to the left in a clockwise manner. As the hammer saddle swings, its cross piece 66 is forced sharply against opposite sides of the notch 54 in the anvil piece 46, thus snapping the contactor bar into and out of connection with the terminals I8 and 20. In this manner contacts are made and broken with a, much-to-be-desired snap action, and thus arcing and sparking, and consequent pitting and erosion of the contacts is avoided.

The last element rotating upon the pin 60 comprises a lever 96, 'which is provided, at its short end,with a downwardly-turned projection 98 that iits behind the extending portion of plate I6 of member '14. A small coil spring |00 (see Fig. 7) encircles the pin 60, and bears at one end against the plate 88, while the other end bears against the projection 98. The coil spring |00 tends to return the lever 96 always to such a position that the projection 98 abuts the plate 16. It will be seen that clockwise rotation of the lever 96 perforce carries with it the member 14, but the lever 96 is free to rotate independently of the lower, and longer end of the lever 96 is provided with an upstanding projection |02, which projection functions in a manner to be indicated hereinafter.

By reference to Fig. 3, it will be seen that the contactor bar assembly, when in off position, assumes such a location with respect to the base that it might well be connecting two other terminals. For this reason, projections |04 and |06 are provided on the base I4, these projections resembling the

projections

22 and 24 with their hexagonal depressions, but being normally undrilled. If it is desired to reverse the order of operation of the switch as a whole (that is, if it be desired that the switch turn on the current after a predetermined off" time, instead of the more normal sequence in which the switch turns off the current after a predetermined on time) the terminals I8 and 20 are mounted on the projections |04 and |06 in place of the

projections

22 and 24. Or, the switch may originally be equipped with terminals on all four

projections

22, 24, |04, and |06, in which event it may be used for either sequence of operations at will or for controlling two circuits (in opposite phases) at the same time. K

This substantially completes the description of the mechanical switching mechanism, and the time delay mechanism will next be described.

'I'he time delay mechanism, broadly, comprises a main spring, an escapement train permitting said main spring to unwind itself only in a slow, controlled manner, anda pair of latches which cooperate with the mechanical switching device to operate the same. 'I'he time delay mechanism is mounted between two brass plates |08 and il@ (see Figs. 4 and 8), which are spaced apart by collars ||2 on screws ||4. The plate |08 is in turn mounted on the pillar 84 projecting from base |4, by means of a screw ||6 that extends through to the exterior of the base I4, and upon a projection or `block ||8 formed integrally with the base I4, in the latter case by means of a strip |20 (see Fig. 7) which is riveted at one end to the plate |08, as at numeral |22, and which is held to the projection ||8 at its other end by a screw |24.

The time delay mechanism as a whole operates upon the mai shaft 23, which, it will be remembered, extends from the front of the switch housing. Said shaft 23 is borne in the plates |08 and ||0, and has mounted thereon, immediately beneath the plate H0, a coiled main spring |26, the inner end of which is securely affixed to said shaft. The outer end of the main spring |26 is secured to a projection |28 struck from the relatively immovable plate I-I0. A main spring cover |30 encloses the spring and prevents it from accumulating dust, etc. 'I'he cover is secured to the shaft 23, and is rotatable therewith.

\ Immediately behind the cover |30 a collar |32 is mounted on the` main shaft 23, the collar |32 serving to space a main gear |34. The gear |34 rotates freely on and relative to the main shaft 23. Immediately behind the main gear |34 is a spring spidermember |36, which comprises a central portion which is secured to the shaft 23 against rotation relative thereto, and a number of radially projecting spring fingers-|38, which are sprung to bear forcibly upon the surface of main gear |34. The frictional force of the iingers |38 on the gear |34 is such that` when the main shaft 23 is manually rotated, as in setting the switch, the fingers slip freely on the surface of the gear, without carrying it in coextensive rotation, but when the main spring alone is tending to unwind, through the escapement train, the slow force is suflicientthat the gear |34 is compelled to rotate simultaneously with the main shaft 23. 'Ihis arrangement constitutes a form of clutch, in which engagement'is had provided the force is applied to the driven member in a very slow, uniform manner, butin which no engagement is had if the force is applied quickly and unevenly (as it is with manual rotation of the main shaft 23). One of the fingers |36, which is separately designated as |40, has a downwardly-turned projection |42 on the end thereof, -the purpose of which will be indicated hereinafterf Behind the spider member |36 on the shaft 23 is mounted a Asmall disc |44, which has a projection |46 in its own plane. The disc |44 is im. movable relative to the shaft 23. Its function.

will be indicated hereinafter. Engaging the main gear |34 is a pinion |48, which constitutes the first element of a timing or escapement train. The escapement train will 75 not be described in great detail herein, since it is of the same type as those shown in my Patents Numbers 1,895,398 and 1,895,399, dated January 24., 1933. Broadly, it comprises a series of pinions |48 and gears |56, which are arranged one gear and one pinion to a shaft, each shaft being supported in bearings in the plates |08 and H0, and which` together effect a large increase (or decrease) in angular rotation from the main shaft 23 to an escapement mechanism |52. 'I'he escapement |52 comprises a toothed wheel |54 and a balance wheel |56, the latter being mounted on a balance staff |58 having a notch |60 Y- therein which, together with a pin |62 mounted on the balance wheel |56 allows the escapement wheel |54 to rotate only one tooth at a time, and at denite intervals. For a further description of the escapement mechanism, reference is made to the copending application of Frederick Franz, Serial No. 410,358, iiled November 29, 1929, for Escapement, now Patent No. 1,934,611, dated November '1, 1933. a

It will now be seen that the operation of the timing means is substantially as follows: ,Assume that the device is initially run down and at rest. The shaft 23 is manually rotated in a direction to Wind the main spring |26 (this direction being counterclockwise in Fig. 8). As the main spring is wound, the clutching mechanism |36 slips and the main gear |34 remains stationary. However, whenever the winding is stopped, the clutching Vmeans |36 immediately takes hold of the gear |34, and further rotation of the shaft 23 andgear |34is simultaneous. As soon as the winding is stopped, there is placed upon the shaft 23 a clockwise torque, by reason of the tendency yof the main spring |26 to unwind itself. The shaft 23, however, cannot now rotate without rotating the main gear |34, and the main gear 34 can 'rotate only in a very slow, timed manner as controlled by the escapement mechanism and' gear train.

Thus, the main shaft 23, after once having been wound, can unwind under its own power only at a predetermined, slow speed. If the shaft 23 is rotated manually in a clockwise (unwinding) ,direction, however, the clutch |36 again slips and the mainA spring may -be manually returned to run down position without awaiting the action of the escapement mechanism.

Supported on a bar |64 which is in turn supported in suitable holes in the plates |08 and I0 is a latch lever |66, the particular construction of which (and of the bar |64) is indicated in Fig. 9. Referring to Fig. 9, it will be seen that the bar 6.4 comprises a stamping of relatively thin sheet metal or the like which has a cross member |68 and` a perpendicular projection |16 extending therefrom. The lever |66 has at one end a rectanguiar hole |112 which receives the cross member |66, the lever thus being non-rotatable on the bar |64. The lever |66 has at its other end an upstanding portion HG, from the front face of which extends, at right angles to the plane of the lever, a projection or latch H6. On the upper surface of the portion is provided a sloping edge or cam which terminates with a projection |89. The cam edge |18 is normally in position to be engaged by the projection |42` of the clutching means |36.-

vthe swingingihammer saddle 62.

and provides a spring force normally urging the latch lever into`its uppermost position.

The plate |68 is provided with an arcuate slot |84 (see Fig. 8) through which the projection I 16 from latch lever 66 extends into the chamber occupied by the mechanical switching mechanisin, in position to intercept or pass the hammer saddle 62 as it swings upon the pin 60. A second arcuate slot |86 (see also Fig. 8) is also provided in plate |08, the slot |86 being arcuate about a center represented by the pin 60 of the mechanical switching mechanism. Through the slot |86 passes the projection |02 of lever 96 of the me- 'chanical switching mechanism, to engage and disengage the projection |46 of disc |44. Since the projection |02 moves about one center, while the projection |46 moves about another'center, it will be apparent that the two will rotate together, in engagement, only for a predetermined distance, after which they will cleareach other.

The above completes the description of the various elements of the mechanical switching device and the time delay mechanism. The 'conjoint operation of the two will now be described.

Assume, again, that the device is initially in run down position, the main spring being unwound. The mechanical switching elements are in their position as indicated in Fig. 3, connections being oi`r. The main shaft 23 is now manually rotated, as by manipulation of the knob |90, in a direction adapted to wind the main spring. For the iirst few degrees of rotation, nothing happens. Then the projection |46 engages the projection |02, and as further rotation takes place, the lever 96 likewise rotates on pin 60. instantaneously the projection 98 on the upper end of lever 96 engages the face of plate 16 of member 14, and forcibly causes the member 14 to rotate along with it, against the spring 80. Rotation Icontinues with lever 96 an'd member 14 rotating evenly with the shaft 23. However, soon the member 14 passes the overcentering position, and the hammer saddle 62 is thrown sharply to the left in the manner hereinbefore indicated t cause the circuit to be closed. Meanwhile the projection |42 of the clutching means |36 has passed from engagement with the cam edge |18, and the latch lever |66 has, under the iniiuence of the spring |82, rotated into its upper position, where its projection |16, which passes through the slot |84 in plate |08, is in position to engage The projection |16 has no effect upon the hammer saddle 62 when the saddle swings from left' to right, because of the sloping lower edge of said hammer saddle (which enables it to 4momentarily push the projection aside), but it is eifective to latch the saddle 62 against rotation from right to left.

With the elements in their Fig. 5 position, further rotation o! a few degrees brings the projection 48 out of'engagement with the projection |02, and the assembly on the pin 60, comprising the member 14 and lever 86, immediately, under the powerful reaction of spring 80, rotates to the left to return to its original position. This return normally would again overcenter the spring 94, and throw the hammer saddle to the left, but the projection |16 is in place and the hammer saddle 62 is thus prevented from swing- 'ing and the current is left on. However, the

spring 94 is cocked in position to swing the saddle 62 as soon as the projection |16 is removed from its path. The position of the elements at the completion of thisstage of the operation is that indicated by Fig. 6.

I the mechanical switching elements.

The switch is now on, and the further rotation of the main shaft 23 is for the purpose of setting the timedelay. While-all of the foregoing has been going on, the main spring has been being wound, but the clutch |36 has been slipping to prevent rotation of the main gear |34. Rotation of the shaft 23 may be continued if it is desired to set the switch for a longer time delay than that already set, or, if a lesser time delay is wanted, the shaft may be rotated in the reverse direction to the required extent. All of this further rotation is without effect upon The time relay to be set, it will be seen, is proportional to the rotation of the main shaft 23 in thewinding direction.

Assuming that the requisite delay has been set, the rotation of the main shaft 23 is stopped, and the escapement means immediately come into operation in the manner specified, allowing the main shaft to return to run down position only at a measured, slow speed. Nothing happens until the device nears run down position, when the projection |42 again comes into contact with the cam edge |18 of the latch lever |66. The shape of the cam edge |18 is such that, at the moment the device returns completely to run down position, the lever |66 is depressed 'to the extent that the projection |16 disengages the hammer saddle 62, whereupon the compression spring 80 forces the hammer saddle 62 sharply to the left, and the contactor bar is rotated to break connection. Thus, at the expiration of the predetermined, set time interval, the connections are broke and the switch goes oi.

At the same time that the switch goes oi, or slightly prior thereto, the projection |46 again engages the projection |02 of lever 96, this time on the reverse side. Thus, the lever 96 is carried along in counterclockwise rotation, it being free to do this because it engages the member 14 only upon clockwise rotation. However, before the device turns off, the projections 46 and |02 have again passed beyond the circumferential region of their engagement,` and the projection |46 has slipped the projection 02 and returned to the original side thereof, in position for al subsequent operation.

At the end of this sequence of events, the switch is again in the position illustrated in Fig. Stand is ready for further operation.

VIn view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As many changes could be made in carrying outA the above constructions without departing from the scope of the invention, it isintended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. A time-controlled switch comprising a pair of terminals, 'a contactor bar movable to connect and to disconnect said terminals, overcentering means for operating said contactor bar, a main shaft, means associated with said main shaft for engaging said overcentering means to operate the same during a fraction of the rotation of said main shaft, a main spring associated with said main shaft, and a timing train connected to said main shaft by a clutching means, means for manually rotating said main shaft, and latching means adapted to intercept the movement of said contactor bar, said latching means being operative according to the position of said main shaft, whereby, upon initial rotation of said `main shaft, said overcentering means is actuated to change the position of said contacter bar, and upon further rotation of said main shaft, said overcentering means is placed in position to return lthe contactor bar to its first position, but is held 'from so doing by said latching means, said timing train thereafter functioning to remove the latching means from operative position after the expiration of a predetermined time interval.

I 2. A time-controlled switch comprising a pair of terminals, a contactor bar movable to connect and to disconnect said terminals, overcentering means for operating said contacter bar, a main I shaft, means associated with said main shaft for engaging said overcentering means to operate the same during a fraction of the rotation of said main shaft, a main spring associated with said main shaft, and a timing train connected to said main shaft by a clutching means, means for manually rotating said main shaft, and latching means adapted to intercept the movement of said contactor bar, said latching means being opera-= tive according to the position of said main shaft, whereby, upon initial rotation of said main shaft, said overcentering means is actuated to change the position of said contacter bar, and upon further rotation of said main shaft, said overeentering means is placed in position to return the contactor bar to its rst position, but is held from so doing by said latching means, said tim-1 ing train thereafter functioning to remove the latching means from operative position after the expiration of a predetermined time interval, the extent of rotation of said main shaft determining the length of said time interval.

3. A time-controlled switch comprising a man= ually rotatable main shaft, an electric switch having open circuit and closed' circuit positions, means associated with said main shaft and ro-l tatable therewith operable upon rotation through a given angle to move said switch from one to another position, and upon rotation through a given greater angle to move said switch back to its rst position, a latching mechanism oper= ated by the vrotation of said main shaft and interposablein the path of said first-named means thereby to prevent, temporarily, said switch from being returned to its rst position, and a timing train operative after a predetermined time interval to remove said latching mechanism from the path of said Erst-named means to permit it to return said switch to its first position.

fi. A time-controlled switch comprising a manually rotatable main shaft, an electric switch having open circuit and closed circuit positions, means associated with said main shaft and rotatable therewith operable upon rotation through a-given angle to move said switch from one to another position, and upon rotation through a given greater angle to move said switch back to its first position, a latching mechanism operated by the rotation of said main shaft and interpos= able in the path of said first-named means there-1` by to prevent, temporarily, said switch from being returned to its rst position, and a, timing train operative after a predetermined time in-I tervai to remove said latching mechanism from the path of said first-named means to permit it to return said switch to its first position, said timing train including a main spring which is likewise connected to said main shaft to he empowered by the rotation thereof.

5. iii time-controlled switch comprising a manually rotatable main shaft, an electric switch having open circuit and closed circuit positions, means associated with said main shaft and rotatahle therewith operable upon rotation through a given angle to move said switch from one to another position, and upon rotation through a given greater angle to move said switch back to its first position, a latching mechanism operated by the rotation of said main shaft and interposable in the path of said first-named means thereby to prevent, temporarily, said switch from being returned to its rst position, anda timing train operative after a predetermined time interval to remove said latching mechanism from the path of said Erst-named means to permit it to return said switch to its first position, said timing train including a main spring which is likewise connected to said main shaft to heempowered by the rotation thereof, the time interval during which said latching means is operable being directly proportional to the angle through which said main shaft is rotated.

MARCUS H. RHODES.