US2539252A - Electric control instrument - Google Patents

Description

E. N. JACOB! ELECTRIC CONTROL INSTRUMENT Original Filed March 11, 1943 Jan. 23, 1951 3 Sheets-Sheet 1 Jmkwd E WETDJXZI Jacubz g 0)? Jan. 23, 1951 E. N. JACOB] 2,539,252

ELECTRIC CONTROL INSTRUMENT Original Filed March 11, 1943 5 Sheets-Sheet 2 l lw" a (IMAM,

Jan. 23, 1951 E. N. JACOB] ELECTRIC CONTROL INSTRUMENT Original Filed March 11, 1943 s sheet 5 Patented Jan. '23, 1 951 2,539,252 ELECTRIC CONTROL INSTRUMENT Edward N. Jacobi, Milwaukee, Wis., assignor to Briggs & Stratton Corporation, Milwaukee, Wis., a corporation of Delaware 1 Original application March 11, 1943, Serial No.

478,763, now Patent No. 2,450,144, dated September 28, 1948. Divided and this application December 29, 1947, Serial No. 794,244

This invention relates to electrical control instrumentalities and refers more particularly to master switches for aircraft.

In aircraft it is customary to provide a separate switch for each engine to control the two magnetos with which the engine is provided for ignition purposes. switches provided for each of the electrical instrumentalities on the aircraft, it is also customary to provide a single readily accessible master switch whereby in an emergency all of the electrical circuits in the aircraft can be broken and all of the engines simultaneously cut off by actuation of a single switch lever. The so-called master switch by means of which this operation is effected is commonly associated with the switch or switches which control grounding of the individual engine magnetos, and it must be so designed that it will make grounding circuits for all magnetos at the same time that it breaks the electrical power supply circuits, and vice versa.

This invention relates to a switch of the master control type which is particularly adapted for use with a pair of magneto control switches and is especially well suited for use in conjunction with the switch described in my copending application, Serial No. 478,763, filed March 11, 1943, now Patent No. 2,450,144, September 28, 1948, of which this application is a division.

It is thus an object of this invention to provide a master switch of the character describedhaving a novel one-piece lever providing both a carrier'for a multiplicity of movable contacts and an actuator for swingin the carrier to and from positions at which it contacts engage cooperating stationary contacts.

Another object of this invention resides in the provision of a novel manner of associating the movable contacts as a unit with the lever of the master switch to thereby simplify assembly of the switch.

"With the above and other objects in view, which will appear as the description proceeds, this in-- vention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the herein disclosed invention may be made as come within the scope of the claims.

The accompanying drawingsillustrate one complete example of the physical embodiment of the invention constructed according to the best mode: so far devised for the practical application of the principles thereof, and in which:

In addition to the usual 15 Claims. (01. 200-7) Figure 1 is an elevational view of a typical switch assembly incorporating the master switch of this invention;

1 Figure 2 is a left side view of the master switch l of this invention,"a portion of a magneto control switch being indicated therebeneath;

FigureB is a rear elevational view of the switch assembly'shown in Figure V Figure 4 is a view similar to Figure 2 but showing the interior of the switch;

Figure 5 is a sectional view taken through Figure 4 on the plane of the line 55;

Figure 6 is a perspective view of theswitch lever illustrating the manner in which the movable contacts carried thereby are assembled with thelever. as a unit;

Figure '7 is a detail sectional view taken, through Figure 4 on the planev of the line l'|;' Figure 8 is a perspective view of the masterswitch housing showin one of the terminal heads separated therefrom;

Figure 9 is a perspective view illustrating the construction of the battery circuit contactor of.

the master switch; and Figure 10 is an exploded perspective view of the components of the guideway for the battery cir-' cuit contactor. Referring now more particularly to the accompanying drawings in which like numerals designate like parts throughout the several views, the numeral 20 designates a switch assembly having.

a pair of individual magneto switches 2| and 22 and a master switch 23.

Since each magneto grounding switch controls, two magnetos and a magneto booster, and since each switch has three positions of operativeness,

designated L, R, and Both in Figure 1, it follows that either of the two magnetos controlled by each switch may be rendered opera-,

tive or inoperative as desired, or that both may be rendered effective. In the off position of the switches the magnetos and their boosters are all rendered ineiiective.

The master switch.23 is secured to a panel 24 centrally and above the two magneto grounding switches 2|, and 22,. and is operated by means ofv a readily accessible lever 21, located between, and

directly above, the magneto switch handles 25.

The master switch 23 is enclosed within a housing '66 formed jointly by a band of brass ll bent to substantially U-shape (see Fig. 8) and a pair of substantially rectangular insulating sheets 18 secured flatwise against the opposite side edges,

of the band so as to provide spaced apart sub-v stantially parallel terminal headsfor the switch.

Opposite lugs 19 bent outwardly from the extremity of the upper leg of the band I! cooperate with a lu 8i] bent downwardly from the extremity of the lower leg of the band to mount the housing from the panel 24- with the open side of the housing facing the rear of the panel and closed thereby.

The two corners of the terminal heads remote from the panel 24 are riveted as at 8I to ears 82 bent outwardly from the band 'I'I, while the upper corner of each terminal head adjacent to the panel 24 is riveted as at .83 to cars 83 bent inwardly from the edges of the band 11.

Spaced apart substantially parallel lugs 84 bent inwardly from the opposite edges of the metal band TI provide for securement of the fourth corner of each terminal head 'to the band and for pivotally mounting the operating lever 21 of the master switch.

The operating lever is medially pivotally mounted on a pin 85 (see Figure '2) and the opposite ends of this pin are received in aligned holes in the lugs or standards 84. The opposite ends of the pin 85' also project through holes in the terminal heads and have rivet heads formed thereon so that the pin which pivotally mounts the lever also provides for securing together the fourth corner of the switch housing.

The inner end 86 of the lever projects into the housing for swinging motion across the opposing faces of the terminal heads and constitutes a contact carrier. For this purpose it is provided with a pair of holes or recesses '81 and 88 spaced different radial distances from the pivot axis.

Identical spider-like brass -.contact members 9| have depressed medial portions 92 overlying the hole 88 at opposite sides of the lever and are joined by a rivet 93 which passes through the hole 88 and'the heads of which limit diverging motion of the contact members. Each of the contact members :has three arms extending radially outwardly from its medial portion to overlie the adjacent face or the carrier '88 and the extremities of these arms have hollow .convex=contact portions 9 3, 95' and .96 engaging the opposing faces of the terminal heads.

The contact members 91 are yieldingly urged apart and into engagement with the inner faces of the terminal heads adjacent thereto by a spring! in the hole 88 .(see Figure In addition, contact pressure for the individual contacts 94, 95 and 96 is aiiord'ed'iby meanssof compression springs 93 passing through suitable holes 99 in the carrier and having their opposite ends received inside the hollow socket-like interiors of the contact portions.

As will be clearly understood from Figure 5, the heads of the rivet 93 do not interfere with yielding engagement of the contacts 94, 95 and 96 with the inner faces of the terminal heads, but prior to mounting of the lever in the housing, the rivet 93 acts to hold the contact members assembled with the lever.

Movement of the contact members '9'I either about the axis of the rivet93 or out of coaxiality with respect to the hole '88 is precluded by lugs I00 projecting from opposite faces of the carrier and engaging various edge portions of the contact members.

A resilient brass grounding connector IilI for each of the contact members 91 has an integral eyelet I02 at one end encircling :the depressed medial portion 92 of its contact member and confined between the adjacent endof the spring 4 91 and the contact member, and another integral eyelet I03 at its other end lying alongside the face of the hub of the lever so as to be disposed between the hub of the lever and the lug or standard. adjacent thereto.

A compression spring 104 received in an annular recess I95 in the lever concentric with its hub yieldingly presses the eyelet 803 of one of the grounding connectors into engagement with the adjacent lug or standard 84.

Thus since the attaching ear of the housing is electrically joined with a ground terminal 58 on one of the magneto control switches by means of a brass connector I06, it follows that the movable contacts 94, and 96 are at all times grounded through an all brass circuit. This is desirable because it eliminates the possibility of electrolytic action which may occur when electrical circuits are led through dissimilar metals.

Stationary contacts 1101, I08 and I69, carried by each terminal head l8 and engaged by the movable contacts 94, 95 and 96 in the off position of the master switch, shown in Figure 4, ground all of the magnetos. For this purpose the stationary contacts Ill-I, I98 and Illa-on each terminal head havecorresponding normally 'ungrounded terminals I91, I08 and H39 exteriorly of the housing electrically connected with the normally ungroundcd terminals E2, 64 and 69 of one magneto grounding switch by short fiexible'conductors as shown in Figure 3.

Consequently, simultaneous engagement of the I six grounded movable contacts 94, 95 and 96 with their cooperating stationary contacts on the terminal heads by actuation of the lever 21 to the oil position of the switch simultaneously connects the normally ungrounded terminals of the four magnetos controlled by the two magneto grounding switches 2| and 2.2 with the ground, regardless of the positions of the individualmagneto switches.

In addition to the stationary contacts previously described, each of the terminal heads 13 has an additional stationary contact IIil exposed on its inner face and connected with a corresponding :battery terminal III! on the exterior contacts IIO simultaneously to disrupt all of' the Upon actuation of the lever 21- battery circuits. to the on positionof the switch, .in which all of the magnetos are under the direct control of" the two magneto grounding switches, the bridging contactor contacts Hi9 to enable the-various electrically operated instrumentalities of the craft to be connected with their source of E. M. F. through their individual switches.

The bridging contactor H! is of special construction to permit its assembly withthe carrier 86 as aunit, andto this end the contactor com-' prises a pair of opposite hollow telescoping plungers II2, substantially rectangular in cross section as shown in Figure *9, which enter the hole 81 in the carrier 86 from opposite faces of 75 the carrier. These plungersareguided foraxial III engages the two stationary.

the jumper motion inthe hole 81 by an insulating guideway H3 serving as a lining for the hole 81. The end portions of the plungers facing the terminal heads 78 are formed with a convex shape, as shown, so as to engagejheconcave faces of the stationary contacts HQ ,with a detent action under the influence of a compression spring H4 confined between the plungers to yieldingly urge the same apart.

A tang. H5 on each of the plungers engages a cooperating shoulder H6 on each side of the insulating guideway to limit spreading apart of the plungers in response to pressure of the spring between them to enable the bridging contactor to be assembled with the carrier 86 prior to assembly of the lever with the housing.-

Although the spring H4 is capable of electricallyconnecting the plungers I I2, it is not relied upon in the present instance other than to press the ends of a flexible braided jumper HI looped about the coils of the spring into firm engagement with the contact engaging ends of the plungers. Thus, since the spring is shunted out of the electrical circuit between the plungers by II'I, the jumper provides an electrical connection between the plungers H2 which insures maximum and undiminished current carrying capacity therebetween.

The rectangular shape of. the telescoping plungers precludes rotation of the same relative to each other about the axis of the hole 81, and in addition provides corner spaces inside the plungers alongside the compression spring I I4 to accommodate two stretches of the braided jumper I I1.

Attention is directed to the fact that the insulating guideway H3 for the plungers of the bridging oontactor is formed of four separate pieces interlocked together and secured in the hole'8'I in a novel manner. Referring to Figures 6 and 10, it will be seen that the hole 8'! is substantially rectangular and that the guideway comprises identical top and bottom plates I I8 and H9, respectively, retained in spaced apart parallel relationship by similar upright side plates I26 and I2I and cooperating with them to form a hollow rectangular unit fitting the hole 81.

The top and bottom plates have a depth greater than the thickness of the carrier 86 so as to project from opposite faces thereof and so that laterally extending shoulders I 22, formed by notches I23 cut into the opposite side edges of these plates, overlie the opposite faces o'f'the carrier 85 alongside the hole 8?. The notches I23 also serve to receive tabs I24 on the top and bottom edges of the side plates so that the top andbottom plates H8 and II 9 hold the side plates spaced apart and parallel and secure them against motion relative to the carrier axially of the hole 61. I

The carrier 86 is provided with a slot I25 leading to the hole 81 but narrower than the hole to provide for assembly of the insulating guideway in the hole. In assembly, the bottom plate I I9 is first inserted into the hole through the slot I25 to its proper position shown in Figure 6; The side plates I20 and *I2I are next inserted so that their lower tabs engage in the notches I23 of the bottom plate, and the top plate is then slipped into its proper position shown in Figure 6 with the upper tabs of the side plates received in its notches I23.

Attention is directed to the fact that the side plates are oi such height that clearance is provided between overhanging ledges I26 on the carrier at opposite sides of the entrance to the hole and the top plate. This clearance permits assembly of the top plate with the guideway and also accommodates a leaf-type spring clip I2T,

the body portion of which is pressed fiatwise against the top plate II8-by tongues I28, bent upwardly from the clip, which yieldingly engage the overhanging ledges I2 6 on the carrier. Other bottoms of slots I30 opening to the front edge of one side plate and to the rear edge of the other side plate, and that there is sufficient v clearance between the plungers of the bridging oontactor and the guideway H I to permit hooking of the tangs H5 of the plungers over their respective shoulders H6 in assembling the contactor with the carrier.

The stationary contacts I01, I68 and I69 have concave faces so that the movable contacts 94,

and 96 engage them with a detent action to define the off position of the master switch,

Attention is also directed to the fact that the terminal heads I8 are provided with recesses- I3I aligning with the opposite ends of the bridging oontactor III in the off switch and into which the plungers of the bridging oontactor snap to increase the positiveness of the detent action at the off position of the switch.

While the detent-like engagement of the plungers H2 of the bridging oontactor with their cooperating stationary contacts H6 defines the on position of the switch, it is desirable to provide at least two recesses I32 in the terminal heads 18 into which each pair of movable contacts 94 and 96 are projected by their springs 98 in the on position of the switch to further guard against accidental actuation 'from said position. It is to be observed that the provision of grounding connectors for the movable contact members 9I permits the lever 21 to be made of insulating material if desired, but the lever is preferably made as a one-piece die casting. If the lever 21 is formed of insulating material,

the insulating guideway for the bridging contactor I I I can be dispensed with and the plungers guided by the hole in the lever itself.

From the foregoing description it will be readily seen that this invention provides an improved electrical control instrumentality of the type adapted to be used as an aircraft master switch which is ofunusually compact and simple construction and which will prove sturdy and dependable in service.

What I claim as my invention is:

1. In a switch of the character described: spaced apart substantially parallel metallic supports adapted to be connected to ground; a lever having a hub substantially medially of its ends pivotally received between said supports, said lever having a hole in one arm thereof the axis of which is parallel to the contact members at each side of said 'arm in a plane normal to the pivot axis of the lever and overlying the hole therein; a compression spring in said hole confined between the contact mempivot axis of the lever;

bers to yieldingly urge the same apart and outwardly from the adjacent faces of said arm;

position of the means passing through said hole andengaging the contact members to limit spreading apart-thereof; a grounding connector for each contact member having a part confined between its adjacent contact member and the spring and having another part confined between one face of the hub and the metallic support adjacent thereto; and spring means reacting between the hub of the lever and one of said connectors for holding both connec tors in engagement with said metallic supports.

2. In a switch of the character described: a switch housing having a metal wall portion adapted to be connected to ground; a lever sub stantially medially pivoted from the housing with one-arm thereof insidethe housing and theother arm thereof projecting outside the housing to provide an actuator for the lever; a movable contact carried 'by the lever arm inside the housing alongside one face thereof for swinging motion therewith about the pivot axis of the'lever and for limited motion relative thereto in a direction substantially parallel to said pivot axis; a stationary contact on the housing insulated therefrom and located so as to be engaged by the movable contact in one position of the lever; means biasing the movable contact outwardly away from its lever arm so that said contacts engage with substantial pressure in said position of the lever; a resilient metal grounding connector for the movable contact having a part maintained in electrical engagement therewith by said biasing means and having a portion disposed alongside said metal wall portion of the housing; and spring means confined between the lever and said portion of the connector to yieldingly press the same into engagement with said metal wall portion of the housing to thereby effectively ground the movable contact.

8. In a switch of the character described: a movable contact carrier having spaced holes therein the axes of which are normal to the plane of motion of the carrier; a pair of movable contacts projecting into one of said holes from opposite sides of the carrier; a compression spring disposed in said. hole between the contacts to yieldingly urge the same apart; an insuiating guideway fixed tothe carrier and surrounding said contacts to guide the same for motion to- Ward and from each other in said hole; coopcrating abutments on the contacts and the guideway for limiting motion thereof apart and for holding the contacts assembled with .the carrie'r; other contact members overlying opposite sides of the carrier adjacent to the hole therein; a compression spring in said other hole confined between the contact members to yieldingly urge the same apart; and means-passing through said other hole and engaging said other contact members to limit spreading apart thereof and to thereby hold the same assembled with the carmen 4. In an electrical switch instrumentality of the type having a housing: a metal contact car rier adapted to be mounted for pivotal motion on an axis fixed with respect to the housing, said carrier having spaced holes therein the axes of which are substantially parallel to the pivot axis of the carrier; a pair of movable contacts projecting into one of said holes from opposite sides of the carrier; a compression spring disposed in said hole between the contacts to yieldingly urge the same apart; an insulating guideway fixed to the carrier and surrounding said contacts to insulate the same from the carrier and to guide the contacts for axial motion toward and from each other in said hole; cooperating abutments on said contacts and the guideway for limitingmation'of the contacts apart and for holding the contacts assembled with the carrier; other contact members :at each side of the carrier ioverlying the other hole therein; a compression:

spring in said other hole for'yieldingly urging} end of said compression spring and the contact:

member adjacent thereto soas tobe held in good electrical contact therewith; and having another portion disposed alongside one .faceof the. carrier adjacent to its pivot axis sooas. to be engageable with a grounded part of the switch housing alongside the carrier; and spring'means confined between the carrier and said lportionrof oneof lthe grounded housing parts for yieldingly urging the same outwardly away from the carrier.

5 In a switch of the type having a housing provided with spaced apart metal wall portions-- adapted to be connected to ground and stationany contacts insulated from saidv metal Wall portions: a lever pivotally supported. from .said

spaced metal wall portions. at a medial pointaoi the lever and with one arm disposed inside the housing to provide a contact carrier; a ,pair of; contacts, one on each side ofthc carrier, bodily movable with the carrier; compression spring means reacting against the contacts to 'y-iclda ingly urge the same into engagementwith said stationary contacts on the housing in one posi tion of the carrier; means for electrically connecting said movable contacts; other contact.

members bodily movable with, the carrier andv overlying opposite faces of the carrier; compression spring means for yieldinglyv forcing said other contact members into engagement with cooperating stationary contacts on the housing in u another position of the carrier; a groundingv com nector for each of said other contact members,

each of said grounding connectors having an apertured end portion confined between the.

spring means and one of said other contact members and having an extension engaged with the metal wall portions of the housing adjacent thereto; and spring means reacting between one of said grounding connector extensions and the lever for simultaneously pressing each of said grounding connector extensions into good :elec'-'- trical contact with said metal wall portions of the housing.

6. In a switch of the character described: two

insulating plates constituting a pair .of terminal heads; a metal wall disposed edgewise between said terminal heads and secured thereto to, hold the same in parallel spaced apart relationship, said metal wall cooperating with the terminal,

heads to provide a switch housing and being adapted to be connected to ground; spaced apart ap-ertured ears on said metal wall overlying the opposing faces of the terminal heads inside the housing; a switch lever substantially medially pivotally mounted between said terminal heads and having a portion inside the housing adapted to swing in a plane parallel to the terminal heads; contact members at each side of said lever portion constrained to motion therewith; spring means reacting against said contact members to yieldingly urge the same toward the inner faces of the terminal heads for engagement with cooperating stationary contacts on the terminal heads in one position of the lever; and means electrically connected with each of said contact members and with its adjacent apertured ear whereby engagement of the contact members with said stationary contacts provides a ground connection for said stationary contacts.

7. Ina switch of the type having aligned spaced apart stationary contacts: a metal contact carrier movable between said stationary contacts, said carrier having a hole therein; a bridging contactor disposed in said hole so as to be bodily movable with the carrier, said bridging contactor having portions projecting from opposite sides of the carrier for engagement with the stationary contacts'in one position of the carrier; and an insulating shell surrounding the bridging contactor, said shell comprising a plurality of interlocked separate insulating plates encircling the edges of said hole to preclude engagement of the bridging contactor with the carrier; and means on certain of said insulating plates engaged with portions of the carrier bounding said hole therein for precluding axial disassembling motion of the shell relative to the hole in the carrier. 7

8. In a switch of the type having aligned spaced apart stationary contacts: a contact carrier movable between said stationary contacts,

said carrier having a hole therein; a bridging contactor disposed in said hole so as to be bodily movable with the carrier, said bridging contactor comprising a pairof opposed electrically connected plungers axially movable in said hole and having contact portions projecting from opposite sides of the carrier for engagement with the stationary contacts in one position of the carrier; a spring confined between the plungers for yieldingly forcing the same apart; an insulating shell in said hole surrounding the plungers to guide the same for axial motion in said hole, said shell comprising a plurality of interlocked separate insulating plates encircling the edges of said hole; means on at least one of said insulating plates engaging portions of the carrier bounding the hole therein for precluding axial disassembling motion of the shell relativeto the hole in the carrier; and cooperating means on the shell and the plungers for limiting axial motion of the plungers apart under the influence of thespring confined therebetween.

9. In a switch of the type having aligned spaced apart stationary contacts: a contact carrier movable between said stationary contacts, said carrier having a hole therein; a bridging contactor disposed in said hole so as to be bodily movable with the carrier, said bridging contactor comprising a pair of opposed hollow plungers substantially rectangular in cross section, said plungers being axially movable in said hole and having contact portions projecting from opposite sides of the carrier for engagement with the stationary contacts in one position of the carrier; a compression spring having its ends telescoped into the hollow interiors of the plungers for yieldingly forcing the same apart; a jumper of flexible low resistance wire inside the bridging contactor having portions confined between the ends of the spring and the inner sides of said contact engaging portions of the plungers to electrically connect the same independently of the spring; an insulating shell in said hole comprising two substantially opposite pairs of insulating plates having interlocking connections with each other to form a guideway substantially rectangular in cross section to receive the plungers and to guide the same for axial motion; means on at least one of said plates engaging portions of the carrier bounding the hole therein for precluding axial disassembling motion of the guideway relative to said hole; and cooperating abutments on the plungers and two of the plates engageable to limit axial motion of the plungers apart under the influence of the spring confined ther'ebetween.

10. In a switch of the type having aligned spaced apart stationary contacts: a metal contact carrier movable between said stationary contacts, said carrier having a hole thereinopening to one marginal edge of the carrier through a restricted throat; a plurality of insulating plates lining the edges of said hole and forming a hollow insulating guideway axially of said hole, one

of said plates extending across said throat at its junction with the hole; means connecting the plates togethensaid means being operable to hold the plates against relative shifting edgewise or toward one another whereby said connecting means cooperates with the edge portionsof the hole to hold the guideway against motion relative to the carrier except in a direction axially of the hole in the carrier; means on at least one of the plates engaging portions at opposite sides of the carrier. bounding the hole therein for precluding axial disassembling motion of the guideway relag tive to said hole; a bridging contactor comprising goopposite electrically connected contact sections telescoped into the insulating guideway from opposite sides of the carrier; a spring confined between said contact sections to yieldingly urge the same apart and into firm engagement with. the

stationary-contact in one position of the carrier;

and cooperating abutments on the telescoping contact sections'an'd the guideway for limiting spreading of said sections apart whereby the bridging contactor may be assembled as a unit 40 with the carrier prior to assembly of the carrier in the switch. l

11. In a switch of the character described: a

pair of terminal heads in'fixed spaced apart relationship parallel to and opposing one another; a

lever pivotally secured between.said terminal heads for motion in a plane parallel to them,

with one arm of said lever extending beyond said terminalheads to form an actuator for the switch and the other arm of said leverlying between said terminal heads and forming a contact carrier; a pair of contactor spiders each positioned between one side of said carrier and the terminal head adjacent thereto and adapted to be carried by said carrier and to engage fixed contacts on the terminal head in one position of the carrier; lug means on the carrier cooperating with said contactor spiders to constrain them to move with the carrier in the plane of carrier motion but leav- 7 ing themlfree to move toward and from the terminal' head; and means yieldingly biasing each of said contactor spiders away from the adjacent side of the carrier and into engagement with the adjacent terminal head. it 12. In a switch of the character described: a pair of terminal heads; means holding said terminal heads in spaced apart relationship parallel to and'opposing one another, said means cooperatingiwith the terminal heads to define a switch housing open at one side; a lever pivoted substantially medially between said terminal heads for motion in a plane parallel to them, one end of said lever extending out of said housing through its open side to provide an actuator for thelswitch and the other end thereof lying within the oilsing and forming a carrier; a contactor spider-positioned: between. each side of. the carrier and its adjacent terminal head and adapted to be moved by the carrier and toengage fixed contacts on the terminal head in one position of the carrier'glug means-on the carrier cooperating with each of said contactor spiders to constrain the spiders to: movement withthe carrier in. the plane ofvits motion but leaving'them free to move in directions parallel to the lever axis; and spring means yieldingly urging each of the spiders into engagement with its adjacent terminal head.

13. In aswit'ch of" the character described: a pair of terminal heads in fixed spaced apart relationship parallel to and opposing one an-- other; a lever pivotally secured between said terminal heads for motion in a plane parallel to them, with one" arm ofsaid lever extending beyond said terminal headsto form an actuator for the switch and the other arm of said lever- 'lyingbetween said terminal heads and forming a contact carrier; a pair of contactor spiders each positioned between one side of said carrier and the terminal head adjacent thereto and adapted to be carried by said carrier and to engage fixed contacts on the terminal head in'one' position of the carrier; means cooperating with said contactor spidersto constrain them to move with the carrier in the plane of carrier 1 motion but leaving them free to move toward and from vtheterminal head; and means yieldihgly biasing each of said. contactor" spiders into engagement with its adjacent terminal head.

14. In a switch of the character described: a pair of terminal heads fixed in spaced apart relationship; a lever journaled on a pivot fixed with respectto said terminal heads, one arm of said lever extending outwardly of the terminal heads to provide an actuator for the switch,

and the other arm forming a carrier'movablein a plane parallel'to and intermediate the terminal heads, said carrier having a hole therethrough,

'the' axis of which is substantially" parallel to the lever pivot axis; a pair of" electrically connected telescoping contactor members in said hole, each extending outwardly therefrom, and adapted to engage a fixed contact on one 01" the terminal headsin'one position of: the carrier; and a spring between said contactor members urging them apart and into engagement with said fixed contacts in said position of the? carrier: so that electric current may beconducted from. the" fixed contact on one terminal head throughtheicontactor members tothe' fixed. contact on: the other terminal head.

15. Anlaircraft master'switch ofithe character described comprising: a pair of terminal heads fixed inzspacedapart; parallel and opposed relationship;: a lever pivotally secured betweenv said terminal heads for motion in auplane parallel to them to either of two positions, one arm of said lever extending beyond the terminal heads to form an actuator for the. switch, and theother arm of said lever lying between. said terminal heads and forming a contact carrier, said contact carrier having a" hole therethrough the axis of which is parallel to the-pivot axis of: thel'ever; a pair of contactor: spiders each positioned. between one side of said carrier and: the terminal head adjacent thereto said contactor spiders being adapted to be carried by said carrier and to engage fixed contacts on the terminal head in one position of the carrier to thereby connect said contacts with ground; lugs on the carrier cooperating with said contactor spiders to constrain them to move with the carrier in the plane of carrier motion but leaving them free to move toward and from the terminal head; means yieldingly biasing each of said contactor spiders into engagement with its adjacent terminal head; a pair of electrically connected adapted to engage a stationary contact on the terminal head adjacent thereto in the other position of the carrier to completea battery circuit across said stationary contacts; and a springbetween said contactor members urging them apart and toward engagement with the terminal heads.

EDWARD N. JACOBI.

REFERENCES CITED The following, references are of record in the file of this patent: v

UNITED STATES. PATENTS Name Date Peterson Jan. 10, 1933 Peterson Jan. 10, 1933

Images