US1317821A - Electric switch - Google Patents

Description

C. D. PLATT.

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"UNITED sTATEs PATENT OFFICE.

CLARENC D. PLATT, 0F BRIDGEPORT, CONNECTICUT.

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To all lwhom it may concern# Be it known that I, CLARENCE D. PLATT, a citizen of the United States of America, residing at Bridgeport, Connecticut, have 1nvented a new and useful Electric Swltch, of which the following is a specification.

, The objects of my present invention are primarily to rovide a simple and compact form of switc` which will have a high current carryin capacity. y

Further o jects are to provide such a switch, which will be relatively inexpensive, which can be easily assembled and which will be of rugged nature and not likely to get out of order.

Briefly, the invention resides in the combination with a movable switch element made up of a cross bar carrying flexible bridging contacts having in-turned contact-making end portions for engagement with relatively stationary contacts and operatin mechanism consisting 'of an oscillating s v aft carrying a lug having a lost motion connection with an actuator vloosely engaged on the shaft and having an operative engagement Another feature of the invention is the provision 4of guide pins whichv are loosely mounted on the switch base so as to permit of the fiexible contacts having a slight slidin movement over the xed contacts.

dditional features of the invention will ap ear as the Aspecification proceeds.

n the accompanying drawin I have illustrated the invention embodie 'in one of its simple commercial forms but would have it understood that variations may be made from this disclosure without departure from the true spirit and scope of theinvention as defined in the appended claims.

In said drawings Figure 1, is a plan view of the invention as embodied in a switch of the inclosed type, the switch box in this case being shown open and the cover partly broken away. In this view also the switch operating handle is shown broken away for a portion of lts Fig. 2, is a sectonalview of the switch taken substantially on the plane of the line 2-2 of Fig. 1, the parts being in the open circuit posltion.

Fig. 3, is a similar view showing the parts in the circuit closed condition.

'Fi 4, is another sectional view illustrating t e parts .at the commencement of the Specication o! Letters Patent.

. stationary contacts, as in Patented Oct. 7, 1919.

Application led May 1, 1919. Serial N0. 294,043.

switch opening movement and illustrating in dotted lines the sliding action of the movable contacts in the course of such preliminary movement.

7 designates the switch base made of suit- -able insulating material and supporting on its face the two pairs of spaced relatively statlonary contacts 8 and 9. These spaced contacts are adapted to bev bridged by thc movable contact members 10 consisting each of a single strip of spring metal having the m-turned or doubled-under end contact portions 11 adapted to bear upon the stationary contacts and connected with the main body o r back of the strip by the rounded loop portions 12.

These in-turned contact-making ends of the strip when free of the statonary`con tacts, as in Fig. 2, stand at an angle to the back of the strip and at an acute angle to the face of the relatively stationary contacts so that in engaging the stationary contacts they will rst touch at the extreme ends thereof at the points indicated at 13 and will then flatten out into firm fiat engagement with the icated in Fig. 3. These arched ends are usually made of spring bronze and of' a suiiiciently heavy gage of metal to roperly carry the current.

14 designates t e cross bar which serves as a carrier for the spring contacts, said switch bar being constructed in the present disclosure of insulating material and ha"- lng the contact strips secured to the end portions thereof by screws 15 passed up through the underside of the strips and into the bar.

The movable switch element described is guided for reciprocating movements toward and away from the base on guide pins 16 over which the bar slidingly fits and these ide pins are loosely engaged in the openings 17 provided therefor in the base.

18 designates the operating shaft journaled above the cross bar and supported in this instance in theo posite side walls of the switch nclosing box or housing 19, said shaft having an angularly extendin handle 20 at the. outside of the box by w ich the switch is operated.

arms of the yoke by a pin 25 and operatn between two spaced lugs 26 and 27 carrie by the side arm 21.

The thrust Vbar 23 at the lower end of the yoke enga a wear plate 28 on the cross bar and w ich is shown secured to said bar by a screw 29.

y The movable switch element is thrust outward to the open circuit osition by a relatively powerful spring 30 aving a seat at 31 in the underside of the cross bar.

In Figs. 1 and 2 the switch is shown in the open circuit position. When it is desired to close the switch, the handle 2O is rocked downwardl This causes the lug or small lever 24, W ich is fast on the shaft, to engage the rearward stop 27 o n the yoke, whereupon the yok`,'acting against the bearing plate, forces the switch bar downward, carrying the flexible arched contacts into firm engagement with the relatively stationary contacts. This final condition is illustrated in Fig. 3. The parts are preferably so proportioned that in this final position the backs of the sprin contacts will be buckled or arched inwar ly, slightly, to increase the tension of the spring contacts against the stationary contacts, thus producing a firm, intimate en agement of the current carryin parts. to be o cned tlzie switch handle is thrown upwardly to bring the lever 24 into engagement with the forward stop 26 of the yoke, as indicated in Fig. 4, a positive connection being thereby a'orded between the relatively fast and loose elements, causing the yoke to be swung downwardly and finally permitting the spring to thrust the movable contact outward with a quick snap, this snap movement being permitted by reason of the lost motion between the parts, as will be clear from a comparison of Fig. 4, with Fig. 2, -the latter indicating the final open position of the switch.

At the commencement of the switch openingl movement the friction between the yoke an the bearing late affords a tem orary connection with t e switch movable e ement which causes the movable switch element to first slide downwardly over the relatively stationary contacts in the manner indicated in dotted lines in Fi 4. This siidin movemen-t of the engage contacts polis es and cleans the engaging surfaces, thereb insuring clean engaging faces and good ectrical contact.

The switch, it will be Seen, is quite sim le but the structure and operation is such t at it is capable of carrying a heavy current, the switch opens with a quick snap insuring a uiclr, positive break 'of the circuit and on e closing of the switch a firm and'positive erigagement of the current carrying parts is a ected. As shown in Figs. 2, 3 and 4 the outstanding Vportions of the spring bridging en the switch is cured fast to the shaft and the other contacts are entirely free to ield in both directions and consequently -t ese contacts can flex and adjust themselves accurately to fit the stationary contacts. This accurate fitting of the relatively movable and stationar contacts is further facilitated by the sli ht sliding adjustment provided for bythe re atively loose guide pins. The parts of the switch furthermore are few in num'ber and relatively simple and are 4such that they can be easily assembled into the complete switch.

I claim:

1. In a switch of the character described, the combination of relatively stationary contacts, a movable switch member for en agement therewith, a switch operatn -sha t, an actuator for the movable switc member loosely ivoted on said shaft, a lug fast to the slia t having a lost motion engagement with the actuator, and a spring acting on the movable switch element in opposition to the actuator.

2. In a switch of the character described, the combination of relatively stationary contacts, a movable switch member for engagement therewith, a switch operating shaft, a yoke having spaced side arms pivotally engaged on the shaft, said yoke being connected with the movable switch element for operating the same, a lug securedto the shaft between the arms of the yoke, said yoke having spaced stops for engagement by said lug, and a spring for moving the switch member.

3. The combination with a switch mechanism including a movable switch element, of an operating shaft therefor and connections between said operati shaft and movable switch element comprising levers mounted on the shaft, one of said levers being secured fast to the shaft and the other being loosely ivoted thereon, and said levers havin a ost motion engagement 'with each o ier and one of the levers making engagement with the movable switch element.

4. In a switch of the character described, the combination of two pairs of spaced relatively stationary contacts, a movable switch element comprising a cross bar and two bridging contacts carried thereby for engagement with the spaced pairs of stationary contacts, an operatn shaft journaled above the cross bar, switch actuating levers on said shaft, one of said levers being seever being loosely pivoted thereon, said levers having a lost motion engagement with each other and one of the levers adapted to engage the cross bar for shifting the same in a switch-closing direction and a spring exerting tension on the cross bar in a switch-opening direction.

5. In a switch of the character described,

tively stationary contacts, contacts for bridging the pairs of stationary contacts and consisting each of an arch of spring metal having in-turned ends adapted to be forced into flat engagement with the stationaryV contacts, a cross bar connecting said arched spring contacts, guide pins on which the cross bar is slidingly engagedeand means for shifting the cross bar to carry the in- Vturned ends of the arched spring contacts into and out of engagement with the re spective stationary contacts.

6. In a switch of the character described, a switch base, pairs of spaced contacts mounted on said base, guide pins 11p-standing from the base a cross bar slidingly engaged on said gui eV ins,contacts carried by said cross bar for ridging the respective pairs' of relativety stationary contacts and consisting each of a strip of spring metal secured intermediate its ends to the cross bar and having in-turned end portions forming spring loops and means for shifting the cross bar to carry said in-turned spring oops into engagement with the relatlvely stationary contacts.

7 In a switch of the character described, a switch base, airs of spaced contacts mounted on said ase, guide pins up-standing from the base, a cross bar slidingly engaged on said guide pins, contacts carried by said cross bar for bridging the respective pairs of relatively stationary contacts and consisting each of a strip of spring metal secured intermediate its ends to the cross bar and having iii-turned end portions forming spring loops and means for shifting the cross bar to carry said in-turned spring loops into engagement with the relatively stationary contacts, said means including a lost motion connection and a spring operating on the cross bar to take up the lost motion with a quick snap in the opening movement of the switch.

8. In a switch of the character described, a base, up-standing guide pins loosel engaged in said base, a switch bar sliding y engaged on said loosely supported guide pins, bridging oontactscarried by said switch bar, spaced contacts on the base adapted to be engaged by said bridging contacts and means for shifting the switch bar to carry the bridging contacts into and out of engagement withl the stationary contacts, said loose guide pins permitting a limited sliding movement of the bridging contacts on the relatively stationary contacts in the course of said switch opening and closing movements.

9. In a switch of the character described, a switch base, spaced contacts arranged in pairs on the switch base, a cross bar guided for reciprocating movement toward and away from said switch base, bridging contacts carried by said cross bar and provided with spring contact portions for engagement wlth the relatively stationary contacts on the base, a box inclosing the switch mechanism and provided with bearing openings in the opposite side walls thereof above Ithe cross Dar, an operating shaft journaled in said bearing opening, a switch actuating member loosely engaged on the operating shaft and having connection with the cross bar for depressin the same toward the switch ibase, a mem er fast on the operating shaft and having a lost motion connection with the loose actuating member and a spring for thrusting the cross bar outward toward the operating shaft.

CLARENCE D. PLATT.

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