US1713201A - Quick-action electric switch - Google Patents

Description

May 14, 1929 i lA. J. VEALJQ` 1,713,21

QUICK ACTIONEAL-ECTRIC SWITCH' Filed March 9, 1926 Patented May 1K4, 1929.

l 1,713,201 UNITEDv STATES PATENT OFFICE.

ARTHUR JAMES vEAIiL, or soUTII YARRA, VICTORIA, AUSTRALIA.

QUICK-ACTION ELECTRIC SWITCH.

Application filed March 9*, 19276, Serial No. 93,408, and in Australia March 17, 1925.

This invention relates to iuiprovements in quick action electric switches and reiers especially to pull switches of thetype usually located on ceilings and operated by pulling on a cord.

Hitherto it has been proposed to make a one way or two-way quick action or snap switch of the tumbler type with a bridge piece pivot-ally supporting a member carrying the blades or movable contacts and in arranging an operating lever and a Tshaped member formed with a stem surrounded by a compression spring whereby when the lever is actuated the movable Contact members move with a dead-centre quick action in theopposite direction. This type ot switch enables a quick make and break to be effected but it cannot be satisfactorily adapted for use-in cases where the switches are required to be placed on a ceiling or other inaccessible position.

The object of the invention is to provide an electric switch of the quick action type embodying simple and durably constructed mechanism operable by a pull cord whereby the contacts will have a quick make and break or non-controllable action and provide efficient service over a lengthy period.

I accomplish the. above mentioned object by providing a switch having iixed contacts fitted to a base supporting a bridge piece furnished with contacts adapted to be oscillated in oppositionto spring pressure'by the operation of toggle members receiving their motion from a crank associated with a pulley which is rotated by pulling on a cord.

The switch can be of the one-way or twoway type and the pulley canA be connected to the member supporting the crank by pawl and ratchet mechanism and acted upon by a spring to return it to its normal position after each operation.

In order that the invention, the object and nature of' which have been clearly set forth, may be readily understood referencewill now be had to the accompanying sheets oi explanatory drawings wherein-h Figure 1 is a view in sectional elevation of a switch constructed inaccordance with the present invention.

Figure 2 is a view in sectional elevation ot the switch taken at right angles to Figure 1. Figure 3 is a view in plan of the switch.

Figures 1 and 2 represent sectional views taken on the dotted lines 1 1 and 2`2` of Figure 3.y

Figures 4, 5 and are views illustrating' certa-1n constructional details which hereinafter will be ij'ully described. L n

Figure 7 is a view in elevation showing certain modifications in the construction and arrangement of parts of the switch.

Figure 8 is a View ot the switch shown in Figure and viewed at right angles thereto.

In Figures 7 and 8 the operative parts oi the switch are shown in full lines and the base and cover are indicated by broken lines.

Figures 9 and 1() are views similar to Figures 1 and 2 and .show further modifications of details in the construction of the switch.

In these drawings the same characters of reference have been employed to indicate the same or corresponding parts in the diiicrent views and the numeral 1 designates a base of porcelain or other insulating material which 1s provided with a recess 2 in which are supported spring contact jaws 3 electricallyassoc-iated with socket or screw terminals t adapted to receive the ends of lead and return wires for supplying current from a mam.

VA bridge piece 5 is secured to the top ofV by means of screws 8 and the sides thereofv can be rovided .vithextensions 9 which are adapte( to be seated in recesses 10 in the base to afford additional rigidity. The recesses 10 may be arranged at one side ot' holes 11 for accommodating screws for securing the base to a support.

The movableA contact blades 7 are insulated and project laterally from the looped or free end of the pivotedk U-shaped member 6. A lug 12 is formed on the looped part of the U-shaped memberanvd this lug is adapted to be engaged byja-ws 13 formed on a head on one end of a rod 111. The opposite end of the rod 14 passes through a hole in a rocking member 15 carried by an oscillatable lever 16 having its outer end pivotally supported on 'the bridge piece.

The free end of the oscillatable lever 16 is formed with jaws 17 having opposed holes adapted to accommodate trunnions 18 on the rocking member embracing the rod,

contact with the` A compression spring 19 surroundstherod 14 andis adapted to bear at one endagainst the head provided With the jaivs 'l'and at the opposite "end against the rocking inem-V ber 15.

The oscillatable lever 16 is slottedi'at Flte be imparted-to the' `disc and the loyer 16`ivill be oscillated to vactuate the movable" contacts?. j

The spring pairlQGis accommodated iiilan annular depression 28 vin the bottom' of the recess 24 and one endA is adapted to engage with the recesses 27 the disc when the pulley is rotated. Then the pulley is return-` ing to itsnormal position'the free end of the spring `pa-Wl 2G ratchets' 'freely over the recesses 27.A j

The fined end of the spring Ypawl 26`passes through a slot Ain the pulley 25 and the projecting vend 29 is A bord SOMis attached to the periphery ot thepulleyand passes around the same and through a cover 31 secured to thebase dor through 'ay hole in the bridge piece. Thefree end ot this cord is provided with a button, tass'cl; or the the cord to rotate the said pulley.

A1 torsion al spring 32s mounted 33 on the pulley and this spring is adapted to exert pressure on the said pulley in opposition. to the direction in whichthe cord is pulled to operate the switch. One end of the torsionalfspring 32 passes through the hole in the fixed-'end or the spring vpaivl Q6 and the opposite end is bent Vover the outer part of the bridgepiece 15, see Figures @and 5.

(1o-acting stops are provided on the pulleyy an d bridge piece to limit the movement of Ithe pulley vvhentlie cord is pulled and to ensure it returning to its normal position* b v`v the action of thefspring V32 `when the cordis released.

The co-acting stops may comprise alateral projection J4 onthepulley anda tail 35 onV the end ofthe spring 32 secured to the bridge piece. The tail ofthe spring- BQis extended tolie in the `path "of A on a boss movementfoi' the projection and the said tail issuiiieiently resilient-to absorbshockand to eliminatenoise whenn struck"` bythe sa-idp'roject'ion uponthe releaseot` the cord.'l j

Th e rio d( 14 provided 'jvith the compression sprin g 19l and theushap'ed member "6 "n'or- Vof the disc to place 1 member 1n line'l with each Y, A formed with a hole V'for the l purpose hereinafter described.

M like in the usualway `to enable'` the same jto be conveniently grasped to pull? mally Vliel atan ang-le to each other and `When the oscillatable lever is moved byl therotation the rod and U-shaped other-the spring 19 Will'be compress-ed and during the further movement of the oscillatable lever and rod the pressure exerted by the spring Will cause the movable contact Ablades to `be moved into or out ot engagement with the spring Contact jawsvvith' a very rapid motion'.y

The toggle action of thelever-androdis sutiioiently i powerfuly to overcome the --resist-J ance of a compression springstr ng` enough to ensure the movable Contact members'being operated ivith a: quick action -rvhenthe pivotal connectionbetweenthe rod andthe U-'shaped member is moved past its dead centre-position.'

Provision is Vmadefo'r positively opening and closing the contacts of vthe switch shouldV theI spring 19i become weakenedl orthe mov-1 able blades become jammed L Abetweenwthe` spring jaws. rlihis object isetfeetedby providing" an Aextension- Bron one=sideioi the-U# shaped member so "that it will 'lie between laterally 'proj ecti-n lstriking `lugs 371011 the free endl or' the oscillatable lever.l Tliestrilring lugs 37 are so `disposed that in the event oi the spring 19 failing j to functionv they rwill` contact with the extension 36 andthebl'ades fill lie moved'into` their opened or closedposition bytlietturtherpull on the'eord. The-lugs 3'!" are Yarranged so that-they Will not `Contact With" the extension 36 in the `event of` Vthe sp ring functioning correctly.

In "the a rrangement"otthe parts' shownin Figures 7 and 8 the rod A1li-is disposed centrally between the arms of the U-shafped memier .(3 land the jawsl thereon are pivoted to an" 'a.rm 38 on a transversely disposed' pivot pin'f) which formedintegrally with a lever 1U having'a slot l1A engaging the. pin 2l dis` posed eccentrically on the disc 22. The slot-- ted lever 40 projects downwardly 4betweenone side of theA bridge-piece 'and theadjacent side oi" the pulleyQ. The upper `end or' the rod 11i in this instance passes througha hole inthe looped end of the Ueshapedmember 6l and the saidhole maybe providedfwitha lining of, insul ating material.

Thebridge piece can be made shorter than shown in Figures 2 andy S and mounted on projections formed on the base, see- Figures- 9 and 10'. Wlhenthe bridge piece Vismounted on the'` projections@ `the :pivots of the U-` shaped member are seated in recesses 43 formed on the opposed inner faces of thefsaid projections i2 and when the rocking member 15 is made ot' non-conducting -material 'the movable contacts are eiit'ectuallyr insulated from the bridge. f

Iii-'Figures 9 and l1() the'invention is shown applied to a double polior tvvo WayA sivitch and Aa modification of the means for positivelyoperating the switch is illustrated.

The modification in the lmeans for positively actuating the movable contacts consists in providing a forkedextension 3G on one arm of the U-shaped member which is adapted to lie'in the path of an extended runnion l5 on one side of the rocking memers. f

The cover 31 for the switch is formed out of sheet metal and is secured to the bridge piece byva screw pin and nut 50, see Figures 1 and 2. i

Alternatively the cover 31 can be secured to the bridge piece by a resilient member such as a spring 51 mounted on the bridge piece and engaging holes or recesses 52 in the cover. The resilient member frictionally engages the recesses in the sides of the cover whereby the cover can be attached and detached simply by pushing it on Lto and pulling it from the bridge piece.

In lieu of arranging the pull cord to pass from the pulley through a hole in the top of the cover it can be passed through a hole 53 formed in one side of the base thereby enabling the said pull cord to be operated in a radial direction (see dotted lines in Figures 1 and 3). This arrangement ot the pull cord will be found convenient when a switch is located high up on a wall or other vertical structure. n

Each time the cord is pulled to partially rotate the pulley the pivotal connection between the rod 14 and the oscillatable lever 16 will be oscillated to cause the said rod and lever to assume an opposite angle to which they were disposed prior to pulling on the said cord and the contact blades to be moved either into or out of engagement with the lixed contacts.

The parts of the switch are so disposed with relation to each other than when the movable contact blades are either in their make or break positions the operation of the pulley by pulling on the cord will cause the eceentrically disposed pin on the disc or pulley to actuate the toggle members (S and 1-l to move the switch blades in a reverse direction to which they were operated upon the previous pull ot the cord, in other words, when the switch has been operated and the cord released to allow the pulley or parts attached thereto to return to their normal positions, the remaining parts of the switch are in their correct relative positions to be again operated.

Then the pulley is returning to its norma-l position after actuating the toggle members to place the movable contacts into a make or break position the resistance of the compression spring on the rod will prevent rotation of the disc or pulley and the ratchet members will move freely past each other under the influence of pressure exerted by the torsional or tension spring acting thereon.

In the foregoing specification I have described a switch embodying the preferred bridge piece, a pulley rotatively mounted on i vthe bridge piece, a pull cord attached to and passing around the periphery of the pull-ey, an oscillatable lever having one end pivoted to the bridge piece, a pin disposed eccentri-y cally to the pulley, a slot in the oscillatable lever engaging the eceentrically disposed pin, a rod having its :tree ends movablyconnected to the U-shaped member and to the free end of the oscillatable lever, and a compression spring surrounding said rod, an extension on one arm of the U-shaped member and lugs on the free end of the oscillatable lever adapted to contact with the extension on the U-shaped member to positively actuate the movable cony tacts when the' switch is operated.

2. A switch comprising a base, fixed con-- tacts on the base, a bridge piece itted to the base, a U-shaped member pivoted to the bridge piece, the bridge piece, a pull cord attached to and passing around the periphery of the pulley, an oscillatable lever having one end pivoted to the bridge piece, a pin disposed eccentrically to the pulley, a slot in the oscillatable lever engaging the eceentrically disposed pin, a rod having its free ends movably connected to the Ueshaped member and to the free end of the oscillatable lever, and a compression spring surrounding said rod, a forked extension on one arm of the U-shaped member, a projection on the oscillatable lever adapted to engage with one or other of the members on the forked extension to cause the movable contacts to be positively actuated when the switch is operated. U

3. A switch comprising a base, lixed contacts on the base, movable contacts co-operating therewith, a bridge piece fitted to the base, a U-shaped member pivoted to the bridge piece, a pulley rotatively mounted on the bridgepiece, a pull cord attached to and passing around the periphery of the pulley, an oscillatable lever having one end pivoted to the bridge piece and having a slot therein, a pin disposed eceentrically to the pulley and engaged by the slot in the oscillatable lever,`

a rod having its free ends movably connected to the U-shapedl member and to the free end of the oscillatable lever, a compression spring surrounding the said rod, a jaw on the free end of the oscillatable lever, a rocking member mounted in the jaw and having a hole a pulley rotatively mounted onv Oppositev endl-of lle'.

in the (lise, a pin clspesed eccentrlcnlly en lle d150 and passmg-tlu'ough the slet 1n [the ose-1llatable lever; said pulley havngehele in 1t@ 51de, an mflgggle shapedy having' one enclfengagmgheprojecting p01'- tlon of the xecl end of the pzu'vl and the Op sw'ltell;, a stop :ouille pulleygaml n mil piece on the end ol: the spllng secured ,to the fixed part of the Swlteh, and pahzolmevement el the smal stop. s f .y

In Wt'hess whereof l hereunto affx my Sgnature.A Y h s" l T 1:1

ARTHUR J. 1111113.

arranged to lie in the 1

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