US2385165A

US2385165A - Electric switch

Info

Publication number: US2385165A
Application number: US512687A
Authority: US
Inventors: Sterling G Sears
Original assignee: Individual
Current assignee: Individual
Priority date: 1943-12-03
Filing date: 1943-12-03
Publication date: 1945-09-18
Anticipated expiration: 1962-09-18

Description

sept. 1s, 1945. s, G, 'SEARS r 2,385,155

ELECTRIC SWITCH Filed Sec. S, 1943 2 Sheets-Sheet l sept. 18, 1945. l s, G, SEARS 2,385,165

ELECTRIC SWITCH Fi'led Dec. 3, 1943 2 Sheets-Sheet 2 y 'am "I" 114 -115 INVENTR.

Jie/l1@ (i Sears BY Patented Sept. 18, 1945 v ELECTRIC SWITCH Sterling G. Sears, Garden City, N. Y. Application December s, 194s, serial Nc. 512,687 12 Claims. (C1. 20o-67) AThis invention relates to electric switches and more particularly to hand operated multiple positionswitches for. successively operating a plu*- rality of contacts. Y l 1 Anobjectof the invention is to provide a'switch oftheabove type in which, various sets of contacts Vare successively operated with a snap action n response to predetermined increments of operating pressure.

Another object is `to provide a novel andimproved switch of the above type which requires a predetermined pressurefor operation, but which may be held in operated position by a substantially smaller pressure.

Another object is to provide a switch of the above type in which the operating pressures may be preselected and controlled in accordance with the'. operetinsrequirements..

., Another object is to provide a switch ofthe above ijs/'pe having novel and improved details of construction and features of operation. ,Various other objects `and advantages will be apparent as the nature ofthe invention is more fully disclosed.

In the drawings,V

will be required. The operating pressure of the spring is determined by the characteristics of the spring, lby the point of application of operating pressure, and by the nature of the abutments.

In one-embodimenteach of the springs, with the exception of the last, is mounted on a mov- (Figli .is atop plan View of my switch mech- A witlrthe top casingsection removed to expose the operating parts; Fig. 2 is a. partial .plan view similar .toFg 1 showing the switch in the rstoperated position with one ofthe contacts'` closed; Figl-S is a. transverse section taken on the line 3f-,3of Fig. 2j y 4 vapartiai detaiiview of the switch in `fully operatedposition with both contacts closed;

5 'is a top plan View similar to Fig; 1 showingia Ymodified form of switch;

6.1s`a'partial plan View similar to Fig. 1 showing a further inodied form of switchinvolving four sets of contacts; ,F'ig. 'I is a transverse section taken on theline 1;*1 of`Fig. 6; and

8 is a detailviewin perspective 'of vthe spring frame. i *In vaccordance withthe present invention, I provide 'aphrality of springs which are 'connected to be' successively operated in' response to progressive increments of pressure on the operating karm oi button.- IEach spring vis designed to operate with a snap action with a predetermined operat ing .pressure and a'predeterminedholding pressure, which maybesubstantially less than the operatingwpressurei. In Vcertain ...instances the spring s et lto remain flexed until manually released.- in lwhich event. no holding pressure able frame which exerts pressure on the succeeding spring.v When the spring having the lowest pressure response has been operated, its operating member bears against a stop, which thereafter causes the spring and its supporting frame to move as a unit and to apply operating pressure to the next succeeding spring, and so on until the entire series of springs has been operated.

Each spring comprises a bowed lead held under compression with its ends in fixed abutments so that transverse pressure causes the spring to flex past its center position with a snap action. The shape of the spring, the character of the abutments and the point of application of the pressure are controlled in a manner to be described so as `to obtain the desiredoperating characteristics.

More speciiicallinthe spring is bent to have two arms of unequal length and the pressure is applied in such a manner that the longer arm iiexes as the spring snaps past its center or snap over position, the angularly disposed shorter arm forming, in effect, 4a movable abutment for the longer arm which facilitates the operation.

The present switch is particularly useful in instances where it is desired to selectively close aplurality of circuits without danger of overcontrol. The switch, may, for example, be used in a combination radio transmitter and receiver with the rst contact set to energize the receiver and the second contact set to energize the transmitter. The operator would apply suillcient pressure to close the ilrst contact when receiving and would apply additional pressure to close the second contact when talking into the transmitter. The switch may also be used for gun re control with the first contact, for example, set to control the ring of tracers and the second contact set to control the firing of ammunition. Various other 'uses will be readily apparent as the nature of the invention is'disclosed.

Referring to the drawings more in detail, the invention is shown in Figs. l, 2 and 3 as applied to a two-position, hand-operated switch vcomprising a base I0 which supports the various elements of thev switch mechanism and forms a part of the housing therefor. The switch mechanism comprises a pair of `spring contact varms Il mounted by suitable means shown as screws I3 on a boss I2 formed on the base I0, and cooperating xed contact arms I4 mounted by means shown as screws I6 on bosses I5. Bosses I5 also carry connector strips I1 to which leads I8 are secured by suitable means shown as clips I9 which are connected to the connector strips I1 by means of screws 2l). The leads I8 extend through a ferrule 2I in the base I0 into a cable 22.

The spring arms. II ,carry clips 25 by means of which lconnection is Imade to leads26 which are connected to terminal pins 21 secured in the base I and extending into a recess 28 which is.v

adapted to receive a suitable connector jack. In the embodiment shown, a through connection is made from the cable 22 by means off-a lead 30 connected to a terminal pin 3I locatedin the" recess 28. One of the spring arms II is also shown as connected to a lead 32 which enters the cable 22, It is to be understood, of course', that the Yconnections to thevarious Contact strips will depend upon the particular circuits in which the switch is'to be used and that the above are shown only by way of illustration. The .spring contact arms II and the fixe Contact arms I4 carry contacts `35and -36 respectively (Fig. 3). InA the embodiment shown, these contacts are adapted to be closedwhen the arms I I are exed into their upper positions and to 'be' opened when the-arms II are exed into -lower positions, although the position may be reversed lto cause the contacts to open when the arms are exed upwardly.

Foractuating the arms II there is provided a pin 38 which extends transversely of the base I0 beneath the arms II in a suitable groove or recess formed in said base. The pin 38 is provided'with recesses 39 in registration with the various spring arms II and dimensioned to a1- low -the spring arms -to rest therein with the contactss in open position. Each recess I39 is formedwith a sloping cam surface 40 which is adapted to raise the corresponding spring arm II into Acontact closing position in response to suitable longitudinal movement of the pin 38. In the embodiment shown the spring arms I I are made-with a circular cross-section as Vshown in Fig; 3L suitedl to ride' up on the cam surfaces 40 for the vabove'purpose.l The cam` surfaces 40 whichvv the respective spring arms II engage are offset-with 'respect to each other so that one'of the contacts, shown'invv the drawings as the lower contact, closes when the pin 38 reaches a rst operatedl position and the second' contact closes when the pin 38 reaches a second operated posi-` tion.`

Fig.` 1 shows the pin 38 in its upper position with both spring arms II'in their corresponding recesses and both contacts open. Figs. 2 and 3 showthe Ypin v38 in its rst operated 4position with the lower spring arm I I riding up on its cam surface 40 4andthe lower contact closed, but with `the upper contact still open. In response to further longitudinal movement of theA pin 38 to the position shown in Fig. 4, the upper contact is closed as its arm also rides kup on the cooperating cam surface.

, The positions of the pins 36 are controlled by a pair of

snap action springs

45 and 46 which are mounted in a recess 41 in the base I0. Each of these

springs

45 and 46 comprises a bowed leaf spring having a bend or curve at a

point

45C, 46C respectively, displaced from the center thereof so as to form

unequal spring arms

45A, 45B and 46A,

46B respectively. At the

points

45C and 46C the spring is preferably bent with a smooth curve so as to avoid sharp corners or deilections which might tend to cause breakage. The spring 45 is formed with a slight bend 45D near the end of its longer arm 45A which may be varied for adjusting the compression of the spring. The spring 46 may be similarly formed if desired.

In the embodiment shown, the spring 4S is -mountedin xed abutments v55 and 56 formed in the base I0 with the Vabutment 55 slightly elevated with respect to the abutment 56 and car- 'n rying the shorter arm 46B.

The spring is mounted on fixed abutments 60 and 6I in an open frame 62 having side walls 63 and end walls 64. The end walls 64 are shown as tapering inwardly and at their bottom edges 65 making a line contact with the lower spring 46 on which they rest. The taper of the walls 64 is such that the line contacts 55 are applied to theA lower spring-46 at predetermined positions in accordance with the pressure to which the spring is to respond. The frame 63 is provided with a cross piece 66 forming astop which is engaged by the spring 45 when in its lower or flexed position. A wall 61 of the base: I0 forms a similar-stop to limit the movement of the Spring 46.

The spring 45 is positioned toA be engaged by the pin 38 at a point determined by the pressure response requirements of the spring. The abutments 60 and 6I are so disposed with. respect to the

abutments

55 and 56 and the corresponding springs that the arms 45A of the spring 45 which is engaged by the pin 38 extends about normal to the pin.

VThe pin 38 is actuated by an operating bar 10 having endanges 1I which engage recesses 12 in the base I0 and are freely movable with respect thereto so that the pin 38 may be actuated by applying pressure to any portion of the operating bar. Itis to be understood, of course, that the operating bar may be hinged at one-end if desired or,` in certain instances, may be replaced by an operating knob, as shown in Fig. 5.

Suitable bosses 14 may be formed on the base 3 I0 adjacent the lower end of the pin 38 for guiding the same and preventing transverse movement. The entire device may' be closed by a suitable cover 15, as shown inFig. 3.

In the operation of this device, the pin 38 is normally in elevated position with both contacts open, as shown in Fig. l. Upon the application of pressure to the bar 10 no movement takes place until sufficient pressure is applied to overcome the resistance of thev spring 45. At this point the spring 45 ilexes with a snap action to the position shown in Fig. 2, thereby causing the pin 38 to move to its first operated position at which the lower contacts are closed.

After the spring 45 has thus been brought against its stop 66, the spring 45 and the frame 63 thereafter move as a unit and apply'pressure to the lower spring 46 at the points of line contact 65. When the pressure on the bar 10 has been increased sufficienthr to overcome the resistance of thefsp'ring 46, this spring likewise w'frlexes with a snapaction to the position shownin Fig- 4 and engages the wall-61 of the base. This action permits movement of the pin 38 to its second operated position for the second pair of contacts.

The force. which is required for actuating each ofthe springs may be determined by the material and dimensions of the springs, the positions of the abutments' and the point of application of force. The abutments may; of course, be made adjustable as shown in Fig. 5 if desired.A

-In the embodiment shown the springA 46 requires more pressure Vfor its operation than the spring 45 because the line contacts 65 apply pressure tothe spring 46 near the fixed ends thereof, whereas the pin 38 applies pressure to the spring 45 near its center. A differential action may thus beV obtained even when springs having substantially identical characteristics are used. The difference in operating pressures is preferably made sumciently great so thatvaccidental operation is avoided and lthe dangerrof an accidental follow `ti'u'ough from one spring to the other is avoided.

- In the above type of spring the holding pressure may -be adjusted independently of 'the acmating pressure by suitable variation of the position of the stop means and the location of the abutments. As the flexing movement of the spring is restricted the holding pressure increases, whereasV if they spring is allowed to flex sufficientl'yv while restrained by suitably xed abutments a point is reached where the spring automatically maintains its exed position without any holding force. The adjustment is preferably such that a substantial force is required to actuate the spring but a minimum holding force is needed, so as to eliminate the danger of accidental operatlonand at the same time avoid fatigue when the contact is to be held closed for a substantial lengthof time.

y Y The provision of spring arms of unequal lengths improves'the operation of the device and permits a une control of the operating characteristics to beobtained.

Referring now to the embodiment of Fig, 5, the features which correspond to those of Figs. 1 to 4 have been given the same reference characters and will not be redescribed. In this embodiment the connector pins 21 and 28 have been omitted inasmuch as all of the leads are shown as takenthroughthe cable 22. This switch is designed Ato be attached tothe end of the cable whereas the previous embodiment is designed to be attached to an intermediate portion of the cable. Also/the operating'bar 18 has been replacedy by a knob 88 merely by Way of illustration.

The arrangement oi the

springs

45 and 46 of Fig. 5 is'similar to that described above. In Fig, 5, however, the spring 46 is designed to operate rst and when operated to retain its operated position until manually released. Consequently, it is not necessary to apply holding pressure after the spring has been actuated. In order to release the spring 46 of Fig. 5 a pin 8| is provided, having a cam surface 82 which is adapted to engage beneath the spring 46 and return the same to its original position. ,Ihe pin 8| extends through the base l and is provided with ,an accessible operating` knob 83. A spring 84 is provided for normally holding the pin 8| in its cuter position.

A screw 85 is shown as bearing against the end of the spring 46 to form an adjustable abutment therefor. A similar screw 86 may be provided in the end wall 64 of the frame 63 to engage the end of the spring 45. By suitable adjustment of the

screws

85 and 86, the operating characteristics of the springs may be varied as desired and the device may be adjusted in accordancewith the use to which the switch mechanism is to be applied.

In the embodiment shown in Fig. after sufclent pressure has once been applied to actuate the spring 46 it remains in its actuated position. The spring 45 may then be actuated and released repeatedly without further actuation of the spring 46. When it is desired to again open both contacts and restore the original position of the springs, the knob 83 is pressed to release the spring 46 and return the same to its original position.

This embodiment may be useful, for example, in combined transmitters `and receivers where it is desired to maintain the apparatus operative without manual attention but to close the transmitter circuit at intervals for talking. At the termination of the operation the apparatus may be again rendered inoperative by actuation of the knob 83.

In the embodiment of Figs. 6 and 7 the invention is applied to a switch having four contacts and four operating positions. In this embodiment the pin |00 corresponds to the pin 38 of Figs. 1 to 4 and is adapted to successively operate a plurality of switch arms |8| which correspond to the switch arms H of Fig. l. Cooperating switch arms |52 correspond to the arm I4 of Fig. l. While only three pairs of contacts have been shown, it is to be understood that any number of contacts may be used, dependent upon the number of springs which are to be successively operated. In the embodiment of Figs. 6 and '7, the pin |08 bears against a spring H9 which is held in a frame the arrangement of the spring H8 and frame l, being similar to that of the spring 45 and frame 63 above described. The frame rests on a second spring I I2 which is held in a second frame H3. The latter frame rests on a third spring H4 held in a frame H5. The frame H5 rests on a spring H6 which is held in abutments H1 and H8 in the base |20.

It is assumed that the spring 0 is designed to operate rst. Thereafter, this spring and its frame operate as a unit to apply pressure to the spring H2, which is designed to operate at a predetermined additional pressure. The spring I2 in turn, after operation, forms a unit with its frame H3, which then applies pressure to the spring H4, which is designed to operate in response to a predetermined further increase in pressure. When this spring operates its frame l l5 applies pressure to the spring H6 and causes the latter to operate.- In this way any desired number of contacts can be successively closed by the application of predetermined increments in pressure. While four springs have been disclosed above, it is to be understood that the number of springs may be varied in accordance with the number. of contacts to be successively operated.

Although certain speciiic embodiments of the invention have been shown for purposes of illustration, it is to be understood that the invention is not to be restricted thereto but that various changes and modifications may be made therein as will bereadily apparent to a person skilled in the art. The invention is only to be limited in accordance with the following claims.

What is claimed ist l. A spring assembly comprising a leaf spring member, xed abutments holding the ends of said spring member againstspreading movement with the spring member bowed, a frame resting on said spring member to apply nexing pressure thereto, a second leaf spring carried in said frame, xed abutments in said frame holding the ends of said second memberv against spreading movement with the second spring member bowed, and means applying flexing pressure to said second spring member to cause the same to flex past its center position with a snap action, said second spring-member being arranged to move as a unit with said frame to transmit flexing pressure4 to said first spring member for causing the latter to flex with a snap action, whereby said springs are operated successively in response to predetermined increments of pressure on said second spring member.

, 2. A spring assembly comprising a leaf spring member, fixed abutments 'holding the ends of said spring member against spreading movement with the spring member bowed, a frame having spaced end supports resting on said spring member at points near the ends thereof to apply flexN ing pressure thereto, a second leaf spring carried in rsaid frame, fixed abutments in said frame holding the ends of said second member against spreading movement with the second spring member bowed, and means applying flexing pressure to said second spring member to cause the same to flex past its center position with a snap action, said second spring member being arranged to move as a unit with said frame to transmit flexing pressure to said first spring member for causing the latter to flex with a snap action, whereby said springs are operated successively in response to predetermined increments of pressure on said second spring member.

3. A spring assembly comprising a leaf spring member, xed abutments holding the ends of said spring member against spreading movement with the spring member bowed, a frame resting on said spring member to apply flexing pressure thereto, a second leaf spring carried in said frame, fixed abutments in said frame holding the ends of said second member against spreading movement with the second spring member bowed, and means applying flexing pressure to said second spring member to cause the same to flex past its center position with a snap action, said second spring member being arranged to move as a unit with said frame to transmit flexing pressure to said rst spring member for causing the latter to flex with a snap action, whereby said springs are opera-ted successively in response to predetermined increments of pressure on said second spring member, each of said spring members having a bend at an intermediate portion thereof dividing the member into tWo angularly disposed spring arms of unequal length.

4. A snap action spring comprising a leaf spring member having a bend at an intermediate portion dividing the leaf spring member into two angularly disposed spring arms of unequal length, fixed abutments supporting the two ends of said spring member and securing the same against spreading movement when transverse pressure is applied, a frame having spaced end supports resting on said spring member at points near the ends thereof to apply flexing pressure thereto, a second leaf spring member similar to said first spring member carried in said frame, fixed abutments in said frame holding the ends of said second spring member against spreading movement with the second spring member bowed, and means applying flexing pressure to said second spring member to cause the same to flex past its center position with a snap action, said second spring member being arranged to move as a unit with said frame to transmit flexing pressure to said first spring member for causing the latter to flex with a snap action, whereby said springs are operated successively in response to predetermined increments of pressurel on said second spring member. s

5. In an electric switch, a pair of spring contact arms, a pin mounted for longitudinal movement beneath said arms and having means-operable in predetermined positions of said pin to successively operate said contact arms, and means actuated byv longitudinal pressure on said pin to cause said pin to assume said predeterminedpositions with snap actions.

6. In an electric switch, a pair of spring contact arms, a pin mounted for longitudinal movement beneath said arms and having means operable in predetermined positions of said pin to successivelyv operate said contact arms, and means actuated by longitudinal pressure on said pin to cause said pin to assume said predetermined positions with snap actions, said last means comprising a pair of leaf springs, abutments holding the ends of said springs against spreading movement with both springs bowed for flexing with a snap action, means applying pressure from said pinto one of said springs for flexing the same with a snap action and means transferring pressure from said first spring to the second spring for flexing the second spring with a snap action.

7. In an electric switch, a pair of spring vcontact arms, a pin mounted for longitudinal movement beneath said arms and having means operable in predetermined positions of said pin to successively operate said contact arms, and means actuated by longitudinal pressure on said pin to cause said pin to assume said predetermined positions with snap actions, said last means comprising a pair of leaf springs, abutments holding-the ends of said springs against spreading movement with both springs bowed for flexing with a snap action, means applying pressure from said pin to one of said springs for flexing the same with a snap action, a frame carrying the abutments of said first spring, said frame resting on said second spring and having means transferring pressure thereto for flexing said second spring with a snap action.

8. In an electric switch, a pair of spring contact arms, a pin mounted for longitudinal movement beneath said arms and having means operable in predetermined positions of said pin to successively operate said contact arms, and means actuated by longitudinal pressure on said pin to cause said pin to assume said predetermined positions with snap actions, said last means comprising'a pair of leaf springs, abutments holding the ends' of said springs against spreading movement with both springs bowed for flexing with a snap action, means applying pressure from said pin to one of said springs for flexing the same with a snap action and means transferring pressure from said first spring to the second spring for flexing the second spring with a snap action, each of said spring members having a bend at an intermediate portion thereof dividing the member into two angularly disposed spring arms of unequal length.

9. In an electric switch, a pair of spring contact arms, a pin mounted for longitudinal movement beneath said arms and having means operable in predetermined positions of said pin to successively operate said contact arms, and Imeans actuated by longitudinal pressure on said pin to cause said pin to assume said predetermined positions With snap actions, said last means comprising a pair of-leaf springs, abutments holding the ends of said springs against spreading movement with both springs bowed for flexing with a snap action,means applying pressure from said pin to aseaic ne of said springs for iiexing the same with a snap action, means transferring pressure from said first spring to the second spring for iiexing the second spring with a snap action, and means adjusting the position of said abutinents for eon trolling the characteristics of said springs.

10. In an electric switch, a pair of spring contact arms, a pin mounted for longitudinal movement beneath said arms and having means operable in predetermined positions of said pin to successively operate said Contact arms, and means actuated by longitudinal pressure on said pin to cause said pin to assume said predetermined positions with snap actions, said last means ccmprising a pair of leaf springs, abutments holding the ends of said springs against spreading movement with both springs bowed for flexing with a snap action, means applying pressure from said pin to one of said springs for flexing the same with a snap action, means transferring pressure from said first spring to the second spring for ilexing the second spring with a snap action and manual release means engaging one of said springs when in a ilexed position for restoring the same.

11. A multiple snap switch comprising a plurality of spring switch arms carrying contacts, a pin slidableA with respect to said arms and having surfaces engaging the same to cause successive operation thereof in diierent positions of said pin, a number of normally bowed leaf springs corresponding to the number of switch arms, xed abutments securing the ends of one of said springs against spreading movement, separate frames carrying the others of said springs, each frame having abutments securing the ends of its spring against spreading movement and having surfaces resting on the adjacent spring, said pin having means engaging one of said springs to .flex the same with a snap action, each frame in turn transferring pressure to the next spring to flex the same with a snap action, said springs having characteristics to cause successive operation in response to predetermined increments of pressure on said pin and determining the successive positions of said pin.

12. A multiple snap switch comprising a plurality of spring switch arms carrying contacts, a pin slidable with respect to said arms and having surfaces engaging the same to cause successive operation thereof in different positions of said Din, a number of normally bowed leaf springs corresponding to the number of switch arms, xed abutments securing the ends of one of said springs against spreading movement, separate frames carrying the others of said springs, each frame having abutments securing the ends of its spring against spreading movements and having surfaces resting on the adjacent spring, said pin having means engaging one of said springs to flex the same with a snap action, each frame in turn transferring pressure to the next spring to flex the same with a snap action, said springs having characteristics to cause successive operation in response to predetermined increments of pressure on said pin and determining the successive positions of said pin, and stop means on each frame to cause the frame and spring to move as a unit when its spring is flexed.

STERLING G. SEARS.