US2637788A - Time-delay attachment for wall switches - Google Patents

Description

May 5, 1953 c. H. BRAcKl-:N

TIME-DELAY-ATTACHMENT FOR WALL SWITCHES Filed April 15, 1952 Patented May 5, 1953 OFFICE TIME-DELAY ATTACHJHENT FR WALL SWITCHES Clement H. Bracken, Pacoima, Calif.

Application April 15, 1952, Serial No. 282,438 6 Claims. (Cl. 200-34) This invention relates to a mechanism adapted for attachment to an electric switch of the wallmounted, toggle type, for tripping the switch at the conclusion of a pre-determined time interval. Many instances arise in which it would be desirable to operate a switch of the type referred to, by a means that will act automatically and without requirement of the physical presence of the user. For example, many homes are equipped with outside lights, for the purpose of lighting a dark driveway, and one leaving the home with the intention of using the driveway is required to switch on the outside light, drive his automobile out of the driveway, and then leave the'vehicle for the purpose of switching oi the light. This is only one instance in which a mechanism of the type stated is desirable, and in recognition of the need for such amechanism, previous 1 switch attachments Aand switch constructionshave been devised for this purpose.

' However, those mechanisms previously devised along this line, of which I have knowledge, have not, so far as is known, found wide commercial favor. This, I believe, may be due to the fact that in some instances, a complete replacement of the conventional wall switch must be vmade, for substitution of anew switch having 'a time delay mechanism incorporated therein. In other instances of which I have knowledge, though the mechanisms are attachable to conventional wall switches, they do not have means incorporated therein for permitting a user to preset the time interval during which the switch is to remain unaffected by the device.

Accordingly, it is one important object of the present invention to provide a time delay attachment for wall switches which can be secured to any conventional toggle switch merely by removal of the screws conventionally employed for securing the switch cover plate in place, and by subsequent attachment of the` device to said cover plate by means `of said screws.

It is another important object to provide a mechanism as described which will be so designed as to permit the user to preset the time interval during which throwing ofthe switch is to be delayed.

Yet another object of importance is to provide a device of the character referred to so designed as not to interfere, in any way, with normai operation of the switch.

Yet another object of importance is to provide a. mechanism as stated which will be of hydraulic construction, the mechanism being so designed as to cause the opposed pressures of a spring and a quantity of pressure uid to act upon the switch tripping means in a manner effective to delay throwing of the switch handle by said means.

Still another object of importance is to pro- :sor

vide a time delay attachment for wall switches which, after being used for the purpose of causing a switch operation after a delayed period, can be reset with maximum ease and facility.

summarized briefly, the invention includes a cylinder adapted to retain a quantity of pressure fluid and having means at one end whereby the cylinder can be attached readily to the cover plate of a conventional wall-mounted, toggle switch. A piston is slidably mounted in the cylinder, and isurged in one direction by a spring interposed between the piston and said end 'of the cylinder. The piston, inthis connection, is provided with a restricted port, so as to slowthe movement of the piston, vdue to resistance on the part of the fluid, when the spring urges the piston in said direction. Means is provided, however, in the piston that will allow free movement of the piston in an opposite direction, for resetting of the mechanism. A shaft is slidable within the piston, and has means at one end adapted to engage the projecting handle of the toggle switch. In operation, the piston travels in said direction within the cylinder, the shaft and piston having means which will be effective to cause joint movement of the shaft and the piston after a predetermined time interval, for tripping of the switch. The shaft, in this connection, can be disposed in either of two positions relative to the piston, in one of which the movement of the piston is slower than it is in the other position, due to a means provided on the shaft for controlling the rate of fluid flow past the piston. In the other position of the shaft and piston, said means on the shaft cooperates with the restricted orice of the piston to accelerate the piston movement, thereby to shorten the delayed time interval during which the switch awaits actuation by the device.

Other objects will appear from the following description, the claims appended thereto, fand from the annexed drawing, in which like reference characters designate like partsthroughout the several views, and wherein:

Figure 1 is a front elevational view of a time delay attachment for wall switches formed in accordance with the present invention, as it appears when mounted upon a conventional switch; "Figure 2 is a longitudinalsectional view, taken vsubstantially on line 2-2 of Figure 1;

' Figure 'i s a sectional view taken transversely of the device, on line 3--3 of Figure 1; y

Figure 4 isr a transverse sectional view through the cylinder of the device, taken on line 4 4 of Figure 2; and

Figure 5 is a longitudinalsectional view through the inner end portion of the shaft element taken on line 5 5 of Figure 2.

Referring tothe drawings in detail, W represents the wall of a room, building, or the like,

3 said wall having mounted thereon a conventional toggle switch having the usual cover plate Ill, and a switch handle I2.

'I'he device constituting the present invention includes a rectangular vmounting plate I4, said plate being flat so as to be positioned against the nat cover plate I0, and being formed with a center opening I5 through which the switch handle I2 extends.

The wall switch is provided with the usual screws whereby the cover plate is secured to the receptacle, not shown, ordinarily associated therewith, and for the purpose of mounting the device said screws are removed, the mounting plate I4 being formed with vertically spaced openings respectively adapted to register with the screw receiving openings of the cover plate l0 of they switch.

When the screws are returned to their proper openings, one screw, designated by the reference numeral I6, is disposed with its head in a fully countersunk. position within the mounting plate, while the other screw, designated by thev reference numeral i8, is so arranged as to have its head projecting partially from the mounting plate A(see Figure 2), for a purpose to be made presently apparent.

Fixedly secured in a suitable mannerl to the lower Vend portion of the mounting plate t4 is a pair of spaced, nat, arms 26', said arms Vhaving spaced apart, (Figure l). Thisin eiiect forms a dovetailed groove, adapted to vslidably receive the dovetail tongue 2li integrally formed upon the upper surface of a circular cap 26'. The capZG is also-1integral a depending, externally threaded extension 2B. the bottom surface of. whichha's a centrally disposed concavity 36. At the center of the` concavity, the cap. 26 is formed, with a depen-ding boss 32v the free end of which projects beyond y ther depending extension 28.

A center opening 34 is. formed in the cap, said opening extending fully therethrough `and being in communication,r as best shown in Figure 2., with a laterally extended vent 36.. The upper end portion of, the opening 34, as will be noted from the drawings, is of enlarged diameter, so as to cause said vent 36. to be in communication withI atmosphere during the operation of the mechanism.,

An elongated cylinder 38 is internally threaded at. its upper end` for engagement with the threads of the extension 218, a sealing gasket 36 being interposed between the cap and cylinder for the purpose of sealing the cylinder against leakage.

The cylinder contains a quantity of pressure A Mounted slide-bly within the cylinder is a piston, 4.2, said piston having its side wall formed, intermediate the upper and'lower surfaces, ofthe piston, withl an annular groove in which is seated a sealing ring M that has wiping contact with the inner surface of the cylinder.

spaced inwardly a short distance from the'v periphery ofi the, piston is an annular series of equidistantly spaced'v apertures, 46 (Figures 2" and 4) and on the'bottoin end of the cylinder there isl provided a depending, circumferentially grooved projection on which is mounted a centrall'y apertured, circular outlet valve 56 formed, of a flexible material. The marginal portion of the outlet valve, as will be noted from Figure: 2, isada'pt'ed t'o close' `the lower ends of the apertures; 46, and vthus 'it will be seen that the Aoutlet valve acts as a check Valve for each aperture 4'6", miliare--v by to close said apertures when the piston lf2 is oppositely beveled inner edges '22 `thus to open said apertures and permit free movement of the piston in said return direction thereoi.

It will be understood, in this connection, that the valve lne'ed not, in every instance, be formed of a flexible material, since said valve, if permittedmovement on its associated projection 48 longitudinally of the cylinder, can move into and out 'of engagement with the underside of the piston for the purpose of discharging its intended functions in a proper manner.

Formed `centrally in the piston 412` .is a port52, saidportopening at one end through the 4projection liti, and. opening at its other end through an upstanding boss 54 Vprovided upon the piston.

A piston .actuating spring 56 is of the coil type, and at .its lower end is circumposed about the boss 5 4 of the piston, in engagement with the upper surface ot. the piston. At its upper end, the spring 56 iscircumposed about the depending boss 32 ofthe .cap 2li.. Thus, the spring 56, when compressed, tends to urge the piston 42. downwardly the cylinder 33.

The invention. vincludes an elongated shaft 58, said shaft being slidabl'y mounted in. the .cap 24 and having one end portion disposed within the cylinder. Said end portion of the shaft extends through theport 52 of the piston 42, being loosely positioned within. said port as will be noted from Figure. i?E 'f As a-result, the port 52 isrestricted iny area, so 'that 'nid flowing `past the piston on downward movement of' the piston will,.by reason oi' itsrbeingl compelled to pass through the restricted 'port 52, causer the movement of the piston under the pressure of the spring 56 to. be slowed considerably.

On the lower .end of the shaft 5.8y is a circuinterential collar 6E, said. collar forming an. abutment` on the shaft onwhich is seated a spring 62..

That end of the shaft 58, onA which the `abut-- ment `6i] is formed has an elongated, axial recess 64 (Figure 5),. and. .communicating between the inner 'end of said recess and the interior of the. cylinder, through the side. wall oi'. the shaft Y58, is an orice 66.

The other end of the shaft projects upwardly beyond the cylinder a substantial distance, and. carries a block` 68 having a recess It receiving the shaftthe shaft having a cross pin 'lZwhereby the block 68 is pivo'tally mounted. upon the shaft.A The. block 66, as will be vnoted .from Figure 2,v has a flat end' surface, lll which, in .one position ot the block, will clear the projecting head of the screw I6, but which will hook under said head in another position to which the. block is pivoted.

In use, and assuming that a long time. interval is .desired before the switch handle I2 is. thrown,

the shaft Ellis pulled upwardly to its maximum extent. This, will cause the piston 42 to be pulled upwardly to such an, extent 'as to substantially close. the, convolutions; ofk the spring, 5.6,. with, all the fluid being disposed below the piston, showngin Figure 2. 'lll*1e1'1,l the user presses the shaftv '58 downwardly to such an extent as to cause the block 68 to be disposed just below the head of the upper screw Il S- 'Theswitch handle r2 is then thrown manually to its 'up or on position.

y The spring 56 tending to expand, will nowiuge the piston '42 downwardly within the cylinder., and this downward movement will be slowedv by the uid 40 in the manner hereinbefore described. After the piston has traveled downwardly along the shaft 58 for a predetermined distance, it will engage the upper end of the spring 62, and this will be effective to begin a slow downward movement of the shaft 58, jointly with the continued downward movement of the piston.

The block 68 will now come'into engagement with the switch handle I2 and movement of the shaft 58 will be temporarily halted by said switch handle. The spring 62, of course, is weaker than the spring 56, so the movement of the piston will continue after the movement of the shaft is temporarily halted. This causes the piston to move past the orifice 66, and the rate of flow of fluid past the piston will now be increased, since fiuid will flow both through the restricted port 52 and the orifice 66. This changes the relation of the pressure of the spring 56 to the resisting pressure offered by the fluid 40, so as, in effect, to increase the pressure of the spring 56. Increased spring pressure, transmitted through the spring 62 and abutment 60, will cause the switch handle to be tripped, so as to operate the switch after the desired time interval.

If it is desired to shorten the time interval, the user pulls the shaft 58 upwardly to its full extent, so as to cause the block 68 to be disposed a substantial distance above the projecting head of the screw I8, with the spring 62 in engage-A that fiuid will flow past ther piston more readily than would be the case if the fluid could pass only through the restricted orifice 52.

As a result, the speed of movement of the piston 42 is accelerated, and said piston will travel downwardly within the cylinder at va Somewhat accelerated pace, carrying the shaft 58 therewith. When the block 68 engages the upper end of the switch handle I2, once again, the movement of the shaft 58 will be temporarily halted, with the piston 42 moving fully past the orifice 66. The final action of tripping the switch handle I2 is the same as in the first instance.

It may be noted that the block 68 is so arranged as to engage the switch handle I2 at the outer end of said handle, thus to increase the leverage desired for tripping of the switch.

It is also believed Worthy of note that the device can be attached readily to a wholly conventional, wall-mounted, toggle type switch, with little difficulty. It is also believed to be an irnportant characteristic of the invention thatfthe user is enabled to preset the time interval, so asv to accelerate the trippingl of the switch if he sov desires.

The entire device, as will be noted, is of relatively simple construction, and in this connection, it will be understood that within the scope of the claims appended hereto, the cylinder could be formed in various ornamental or inconspicuous designs, to harmonize with the interior of the structure in which the device isY being used. The device can, of course, be used exteriorly of a building if it is so desired. l

It may be noted that the device does not interfere with normal operation of the switch, when it is not desired to use the device. In such instances, the shaft 58 is rotated 180 degrees from the position thereof shown in Figure 2, and the underside of the block 68 is allowed to rest upon the tongue 24. This leaves the switch handle I2 lfully exposed, and unobstructed by the device, to

for any purpose to which it may be suited. Nor

is the invention to be necessarily limited to the specific'construction illustrated and described, since such construction is only intended to be illustrative of the principles of operation and the means presently devised to carry out said principles, it being considered that the invention comprehends any minor change in construction that may be permitted within the scope of the appended claims.

What is claimed is:

' 1. In a time delay attachment for Wall switches of the toggle type, a cylinder having a quantity of pressure fiuid therein; a piston working in the cylinder, said fluid and piston being relatively arranged to slow movement of the piston in one directionv within the cylinder; a shaft slidably mounted in one end of the cylinder, said shaft having one end extending into the cylinder and the piston having a slidable mounting on said end of the shaft; means on the shaft engageableV by the piston, after slow movement of the piston in said direction longitudinally of the shaft over a predetermined distance, for effecting joint, slow movement of the shaft and piston; a spring engaged between one end of the cylinder and piston, said spring being tensioned to urge the piston in said direction; and means on the shaft adapted to engage and trip the handle of a wall switch aftersaid slow movement of the shaft over a predetermined distance. Y

2. In a time delay attachment for wall switches of the toggle type, a cylinder having a quantity of pressure fluid therein; a piston slidable in the cylinder, vsaid piston having a port for the passage of fluid therethrough and said port being of a restricted size so as to slow movement of the piston in one direction within the cylinder; a shaft slidably mounted in one end of the cylinder, said Shaft having one end extending into the cylinder and the piston having a slidable mounting on said end of the shaft; means on the shaft engageable by the piston after slow movement of the piston in said direction over a predetermined distance, for effecting joint, slow movement of the shaft land piston thereafter; a spring' interposed between one end of the cylinder and the piston, said spring being tensioned to urge the piston in said direction; and means on the other end of the shaft adapted to engage and trip'the handle of a wall switch after said j slow movement of the piston Iand shaft over a predetermined distance.

3. `In 'a time delay'attachment for wall switches of the toggle type, a cylinder having a quantity of pressure fluid therein; a piston slidable inthe cylinder, said piston having a port for the passage of fluid therethrough and said port being of restricted size to slow movement of the piston in one direction within the cylinder; a seriesof check valved apertures in thepiston arranged to permit free movement thereof in an opposite direction; a shaft slidably mounted in one end of the cylinder, said shaft having one end portion extending into the cylinder and loosely positioned through said port, for slidable mounting of the piston on said end portion of the shaft; means on the shaft engageable by thepiston after slow movement of the piston along the shaft in said one direction over a predetermined distance, for

fantasmas piston ythereafter in the same direction; afspring interposed between one end foif't'he rcylinder 'and :the piston, said spring being tensioned to urge 4the piston in saidonedirection; and lmeanso1i rvthe other endportion'of the shaft-.adaptedvto env'gage and trip thehandle fof a wall switch after said slow movement 'of the piston and lthe shaft 'over yaf predetermined distance. f

4. 'In a time delayattachment-for wallswitches of theftoggle Itype, a cylinder .having ya .quantity -ofipressure -)fluidi-,herein; a piston sldableiin the cylinder, said pistcnnavng a port-for ythe 'passage of =fluid Ytherethroughandisaid port being of a restricted size to slow movementof the piston in one direction Within the cylinder; a series of check valved apertures in the piston arranged to permit zfree movement thereof in .anopposite direction; `a shaft slidablyrnountedin Yone `end of the cylinder, said .shaft having one end .portion extending intofthe'cylinder and looselypositioned through .said port,.forslidable mounting ofthe piston on saidfendportion of the shaft; anlabutmention said endportion vofthe shaft; ;.a :rst

springcircumposed aboutfthe shaft and'seated on saldabutment, said spring being engageable. by the ypiston l.a1`te1..s'lovv movement ofthe piston along the shaft insaid one direction for effecting joint, slow .movement of the shaft and piston thereafter in thesamedirection; a second .spring interposed between .one end ofthe cylinder and the piston, said-second spring being tensionedto urge'theipistonin said one direction; and :means ori-the other end portion of the-shaft adapted to engage and Itrip the -handleof a. wall lswitch after said slow movement of the piston and shaft Jover a predetermined distance.

`5. In a time delayattachment for -wallswitches of `the toggle type, -a cylinder ihavinga-quantity of pressure fluid therein; :a piston slidable in the cylinder., .said piston having aaport forthe passage of fluid therethrough and saidport ybeing of ra restricted .size .to 'slow movement of the piston in one direction within the cylinder; a :series of check Aval-ved apertures inthe pistonarranged to permit free movement thereof in anzopposite direction; a shaft slidably mounted in .onefendiof the cylinder, said shaft Ahaving one endzportion extending into the cylinder and vloosely ,positioned through said port, for rslidable :mounting of the Ipiston on saidend portion of the shaft, said end portion of the shaft having an elongated, axial .recess vand an .orifice communicating vbetween said recess and the-interior .of the cylinder through the side .wall .of .the shaft at .a Alocation spaced .from ,the adjacent vend of fthefshaft; an abutment on said end .portion of the shaft; 1a first spring circumposed .about the .shaft and seated on said abutment, said lspring :being engageable by the piston after slow movement of the piston along ythe shaft in said one .direction ya predetermined distance, ,f or effecting joint, slow movement ofthe shaft and piston thereafter in thegsame direction; a secondspring interposed between one .end of the cylinder and the piston, said second vspring being tensioned ,to ,urge the piston in said one direction; kand .means on .the other endportionof .the shaftadapted to engage the handle vof av wallswitch after ,said joint, `slow movement of the piston and shaftover a predetermined distance, for Atemporarily.halting movement of the shaft duringcontinued movement .of said piston in the same direction Yunderpressure `of the second spring, `said pistonl and orifice be- VVing'arranged for movement ofthe piston pastfthe :orifice after'said temporary halting of the shaft,

vwhereby Ato eiect movement of fluid past vthe pistonthrough both the port and orifice' 'and :thereby rdecrease the `resistance offered by the fluid to movement of the piston, thus to eiect trippingjof the handle by said means under vthe yproportionately increased pressure -of the second spring Vagainstithezpiston.

l6. In atirnf,l del'ayattachmentfor-wall switches 'of fzthe '.togg1e1type, ya `cylinder yhaving a quantity vof pressure .fluid therein; a cap detachably con vnected to fone end `of fthe cylinder; a mounting plate adaptedto be'secured ytothe cover plate of a .wall switch,'said cap and'mountingrplate havving `cooperating lmeans r`tor detachable connection :of :the 4capto the mounting'plate; a .piston slidable in theicylinder, said'piston having a port for 'the passage .of fluid -therethrough and said .portibeing of a restricted size to slow movement `oft-'he piston in one-direction within the cylinder,

the piston havinga series of check valved aperitures arranged to .permit free movement ofthe piston. `in ,an oppositezdirection; -a shaft slidably mounted in said cap, saidshafthaving. one end portion -fextending into the cylinder. and loosely positioned through saidiport, for slidable mounting of theipistonpn said endvportion of the shaft, said end. portion of the shaft having an elongated, axial-recess :and .an orice 'communicate ing vbetween saidrecess .and the interior of the cylinder througl'i the .side Wall .of `the shaft ,at aI :location spaced .from the adjacent end of the shaft; lanabutment on said end portieri of--the shaft; a first springcircumposed.about the shaft and seatedonesaid abutment, said spring being engageablefby the `piston fafter slow movement of the `piston along vthe shaft in said one direction, foreiectingnjoint, :slow movement of the shaft andypiston thereafter in the same directioneJ second spring interposedbetweenfthe cap'andthe piston, said.secondzspringfbeing'tensioned to urge the piston vin said one direction; fand a block pivotally `mounted on the -otherfend portionjof the shaft vand adapted Ito engage the handle of a wallswitchafter said joint, slow movement of the piston andjshaft overa `predetermined distance, for temporarily haltingmovement ofthe shaft duringcontinued movement of `said Vpiston in the same .direction under pressure :of the second sprng,-said :piston .and oriice being arranged for movem'entzof the=piston past the-oriiice aftersaid temporary halting of theshaft, whereby to effect movementtof fluid past lthe'fpiston through both the vport rand orifice and thereby decrease the resistanceoiered :by the fluid to movement 4of the piston, thus to eifect a tripping of the handle bysaid block under the proportionately increased pressure ofthe second spring against the piston.

CLEMENT H. BRACKEN.

References Cited in the "file -of .this patent l 'STATES' PATENTS liillrnbervl`` u Dnmalll 31.11.18 7, 1909

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