US3038981A - Push-push operating mechanism and electric switch utilizing same - Google Patents

Description

June 12, 1962 K1N i 3,038,981

R. E. LAR PUSH-PUSH OPERATING MECEANISM AND ELECTRIC Filed Aug. s, 1959 SWITCH UTILIZING SAME 3 Sheets-Sheet 1 1 loj m) so se 5'3 o sob o '42 June 12, 1962 PUSH PUH Op' Ff E'RRIN ERATING MECHANISMAND. ELECTRIC 3,038,981 SWITCH UTILIZING SAME 5 Sheets-Sheet 2 Filed Aug. 5, 1959 a u *Il una 2 ANISM AND ELECTRIC E 3038981 zING SAME LARKIN NG MECH UTILI 5 Sheets-Sheet 3 UnitedN States Patent O' ware Filed Aug. 3, 1959, Ser. No. 831,425 11 Claims. (Cl. 200-153) This invention relates to a push-push operating mechanism and electric switch incorporating the same.

The primary object of the invention is to simplify the structure detail and to improve the operative characteristics of a push-push operating mechanism.

Another object is to provide an improved electric switch which incorporates the aforementioned operating mechamsm.

Other objects and advantages of the invention will hereinafter appear.

The accompanying drawings illustrate a preferred embodiment of the invention ywhich will now be described, it being understood that the embodiment illustrated is susceptible of modifications in respect of details without departing from the scope of the appended claims.

In the drawings:

FIGURE l is a front elevational view of an electric switch incorporating the invention;

FIG. 2 is a horizontal section view to larger scale taken along the line 2-2 of FIG. 1;

FIG. 3 is a. vertical section View taken along the line 3--3 of FIG. 2 and showing the switch in one extreme operating position;

FIG. 4 is a fragmentary vertical section View showing the switch in an intermediate operating position;

FIG. 5 is Aa View, like FIG. 4, but showing the operating mechanism in another extreme operating position;

FIG. 6 is a perspective view of a contact lever shown in FIGS. 2 through 5;

FIG. 7 is a vertical end section View of the switch taken along the line 7--7 of FIG. 3;

FIG. 8 is a perspective fragmentary section View of a molded base taken essentially along the line 8 8. of FIG. 2; and

FIG. 9 is a perspective view of a lever shown in FIGS. 3, 4, 5 and 7.

As shown in FIGS. l through 3 and 7, the switch illustrated comprises a molded insulating base 10, an insulating cover member 12, a metal securing and supporting frame 14, a threaded one-hole mounting bushing 16 and a molded insulating push-button 18. The housing 10 has a main recess 2i), opening yto the top thereof, like recesses 22 and 23 which are separated by an intermediate wall 10a which communicates at one end with recess 2'0' and open to the -top and one side of the housing 10'. Base 10 is also provided with an `auxiliary recess 24 which opens to the top and opposite end of housing 10. Cover member 12 overlies the recesses 20, 212, 23 and 24 and has an opening 12a therein registering with the upper end of main recess 20. The frame `14, which is preferably formed by punchinfy and stamping of ya sheet metal plate, comprises a top portion 14a overlying a portion of the cover lf2 and including an opstanding boss portion 14b which overlies the aforementioned opening 12a in cover 12 and upper end of recess 20. Frame 14 further comprises vertioally depending side portions 14C and 14d which at their upper ends integrally connect with the portion 14a and engage with the side walls of the housing 10. Each of the portions 14o and 14d at their lower ends are provided with tabs 14e which are inwardly clinched into recesses 10b formed in the outer bottom wall of the housing 10 to secure the frame cover member 12 and housing 10 in the Iassembled relation shown. A threaded 3,038,981 Patented June l2, 1962 cylindrical bushing 16 has `a llower unthreaded portion of reduced diameter 16a which extends into a circular opening formed in the boss portion y1li-b of frame 1.4 and is spun over on the underside thereof -to secure the same rigidly in place.

A molded insulating fulcrum member 26 is disposed in main recess 20 and is provided with a downwardly opening cylindrical recess 26a within which is seated one end of a coiled compression spring 28. The spring 28 at its lower end is disposed about and is retained against lateral vdisplacement by an upstanding cylindrical boss 20a formed in the bottom wall of recess 20. Member 26 is provided with integrally formed lugs 2Gb on opposite sides thereof which project into guideways 2017, formed in the opposite side walls of the recess 20 to restrict member 26 against any appreciable lateral or rotary displacement in recess 20. At its upper end member 26 has an inverted V-shaped fulcrum bearing portion 26e. Integral upstanding lug portions 26d and 26e are disposed in opposite sides of the bearing portion 26C.

A contact operating lever 30, prefer-ably formed by lthe punching and stamping of a piece of sheet metal, is provided with a portion 30a bent at shallow obtuse angle. The inner intersection line of the angle seats on the apex of the fulcrum portion 26e of member 26. Lever 30 is lalso provided with bifurcated contactor arms 30h and 30e, each of which carries a contact tip 30d, which in one preferred form is formed of a suitable low resistance electrical contact material. The portion 30a has short lugs 60e extending outwardly on opposite sides thereof ywhich project within the guideway 201: of recess 20, to thereby prevent any substantial `lateral or rotational movement of the lever 30' on recess 20. The notch between the contactor arms 30e and Sild straddle the lug 26e and on the opposite side of the contact lever the portion 30a is provided with a notch 30f to clear the other lug 26a'.

The wedge shaped portion 32a of a driving lever 32, which is preferably formed of a suitable molded insulating material, bears on the upper surface of the portion 30a of contact lever 30. Driving lever 32 has a rectangular upper end portion. 32h and lug portions 32e and 32d depending from the opposite sides of the portion 32a. The portions 32e and 32d at the upper ends thereof are provided with bearing journals 32e which extend into the bearing recesses 33 formed in the base 10 and opening to the top thereon into recess 20 on one side thereof. Portions of the cover 12 overlying the top of the recesses provide for closure thereof. In the bottom wall of the recesses 33 are formed side-by-side arcuate bearing surfaces 33a which are separated by the ridge 3317. The wedge shaped portion 32a of driving lever 32 has edge surfaces 32f and 32g. As will be hereinafter more fully explained, the surfaces 32] or 32g are adapted to bear and slide along the upper surface of the portion 60a of contact yoperating lever 30 as the switch is operated from one position to another.

A cylindrical cup-shaped member 34, preferably formed of a molded insulating material, ts within the cylindrical bore 1611 of bushing V16 and is adapted to be reciprocably moved therein. An internal cylindrical recess 34a in member 34 accommodates the lower end portion of a coil compression spring 36 which seats at its lower extreme end against the bottom wall of the recess 34. At its upper end spring 36 is disposed about the lower reduced cylindrical end portion 38a of a pushrod 38. Pushrod 38 is provided with a main stem portion 38b of cylindrical form which is adapted to reciprocably move in the upper internal bore 16c of the bushing 16. Pushrod 38 is provided with an integrally formed llange 38C which is adapted to engage with the shoulder formed at the junction of the bores 1Gb and 16C in bushing 16. Flange 38c limits the outward movement of the pushrod relative to 3 bushing 16. At its upper end pushrod 38 is provided with a reduced end portion 38d having a bulged portion 38e thereon, and the push-button 18, which is preferably formed of a molded insulating material, is adapted to seat therearound with a forced tit.

A pair of substantially L-shaped contact-terminal plates 40 are adapted to seat within complementally formed ledges 22a and 23h in the recesses 22 and 23, respectively. The horizontally depending portions 40a of the terminal plates are provided with rectangular corner notches to accommodate rectangular lugs 22b and 23h, respectively, formed on each of the opposite side walls of the recesses 22 and 23, for securing the terminal plates against any lateral movement. As will be noted the cover member 12 prevents any substantial upward movement of the contactterminal plates 40 in the recesses 22 and 23.

Down turned rectangular tabs 42a of V-shaped spring clips 42 seat within rectangular side recesses 22e and 23e formed in the opposite inner side walls of the recesses 22 and 23. The limbs 42b of the spring clips 42 underlie the cover 12 and the latter serves to hold the clips in place with the tabs 42a bearing against the bottom surfaces in recesses 22C and 23C. The integrally formed limbs 42C project at an angle from the limbs 42h and terminate at a free end which is spaced a given distance apart from the horizontally depending portions of the contact-terminal plates 40. The spring clips `42 are preferably formed of a resilient metallic material and bared electrical conductors of appropriate `diameter are adapted to be inserted between the free end of the limbs 42e and the upper surface of the portions 40a of contact-terminal plates 40. If a force tending to pull the conductors outwardly is exerted, the end of the limbs 42C are adapted to bind the wire conductor against the contact-terminal plates 40 and hold the same securely in good conducting engagement. As will hereinafter be more fully explained in a given operating position of the switch the contact tips 30d of the contact lever 30 are adapted to abuttingly engage with the lower surface of the limbs 40a of the contactterminal plates 48.

A substantially L-shaped terminal plate 44 is adapted to seat within complementally formed ledges 24a in the recesses 24. The lower horizontally `depending limb 44a of terminal plate -is provided with rectangular corner notches which are adapted `to accommodate rectangular lug portions 2'4b formed in the recesses 24 for holding terminal plate 44 against any substantially lateral movement. A V-shaped spring clip 46 has rectangular tabs 46a formed on either side thereof which extend downwardlyv and seat within rectangular recesses 2412 formed in the opposite side walls of recess 24. The cover member 12 overlying the tabs 46a and the upper horizontally disposed limbs 46b and 46c of terminal plate 46 holds the same in place in the housing 10. The integrally formed lower depending limb 46c of terminal plate 46 terminates at a point spaced apart from the upper surface of the limb 44a of terminal plate 44. As will be noted the terminal plate 44 and spring clip 46 has no electrical connection with the switch mechanism or the terminal plates 40 and the spring clips 42. The function of the spring clip 46 and terminal Vplate 44 is that of a bussing terminal, whereby certain wires may be conveniently electrically connected by common engagement with the terminal plate 44 and the spring clip 46.

FIG. 3 depicts an off operating position of the switch. lf pushbutton118 is depressed inwardly of the bushing 16, pushrod 3S will compress the spring 36 and engage the langep38c with the upper rim of cup 34 and the force will be transmitted to the upper right-hand corner of the portion 32b of driving lever 32. This force is then transmitted` from the surface `32g of lever 32 to contact operating lever 30 and thence from the latter to the member 26. When this force is great enough the compression spring 28 is caused to be compressed and member 26 and operating lever 30 are caused to move downwardly within the housing 10. Concurrently driving lever 32 is first to be caused to move downwardly so that its bearing journals 32e move from the upper left-hand bearing positions depicted in FIG. 3 to engage one of the left-hand arcuate bearing surfaces 33a as depicted in FIG. 4. Continued inward movement of the pushbutton thereafter causes driving lever 32 to be pivoted clockwise (as viewed in FIGS. 3, 4 and 5) on its journals 3211. In so pivoting the surface 32g of the wedge shaped portion of the lever slides along the upper surface of portion 30a toward the apex of the fulcrum, and when pushbutton 18 has reached the limit of inward movement, it has ridden over the outer intersection of the angle on portion 30a and pivots lever 30 counterclockwise to engage its contact-s 30d with the lower surface of the portions 40a of contact-terminal plates 4t). The operating position assumed by the switch parts at this point is that depicted in FIG. 4.

When pushbutton 18 is thereafter released, the stored energy in the compressed spring 28 causes member 26 to move upwardly, and the force transmitted through the portion 30a of lever 30 to the surface 321 of driving lever 32 causes the latter -to rst pivot again in the clockwise direction and slide its surface 32f on the upper surface 30a of lever 30. Upon further upward movement of member 26 driving lever 32 is caused to be moved upwardly so that its bearing journals 32e move olf the lower left-hand arcuate bearing surfaces and move diagonally into the upper right-hand bearing positions in recesses 33 depicted in FIG. 5. Simultaneously contact lever 30, due to the upward movement of member 26, pivots a slight degree in the clockwise direction but in so doing maintains continuous engagement of its contacts 30a with contact-terminal plates 4t). The combination of the downward linear land clockwise pivotal movement of lever 30 results in a certain degree of sliding of the tips 30d on contact-terminal plates 40. When pushbutton 18 reaches its fully released position the position of the switch parts will be that depicted in FIG. 5, This is `the on position of the switch with electrical circuit being completed between the two contact-terminal plates 40 through contact lever 30 which has its contacts 30d held in engagement therewith. This position will be maintained until pushbutton 18 is again depressed.

Starting with the switch operating position depicted in FIG. 5, inward depression of pushbutton =18 will cause driving lever 32 to be moved downwardly so that its bearing journals move into the lower right-hand arcuate bearing surface 33a in the recess 33, and upon continued inward movement of pushbutton 18 will pivot counterclockwise (as viewed in FIGS. 3, 4` and 5) `and slide its edge surface 32f to the right on the upper surface of the portion 30a of lever 30. When the apex of the wedge shaped portion passes over center of the fulcrum apex of member 26, it pivots lever 30 clockwise to disengage contacts 30d from the lower surface of the contact-terminals 40. The combination of upward lineal movement and counterclockwise pivotal movement of lever 30 results in a `certain degree of sliding of the tips 30d on contactterminal plates `40. Upon subsequent release of pushbutton #18 the stored energy in spring 28, acting through member 26 and lever 30, first causes further clockwise (pivotal movement of driving lever 32 `and then diagonally moves it so the bearing journals 32e move `out of engagement with the lower right-hand arcuate bearing surfaces 33a and into the upper left-hand bearing positions depicted in FIG. 3. The nal positions of the switch operating parts will be that depicted in FIG. 3; the off operating condition of the switch.

As will be understood, any two subsequent inward movements of pushbutton 18 alternated with release of the same will repeat the operation cycle aforedescribed. Y The laforedescribed sliding action of the contact tips 30d on the contact-terminal plates 40 just 4after engagement and just before disengagement is advantageous. It

snee,

insures use of dilferent initial and iinal areas and helps to keep such contact areas clean.

The use of compression spring 36 between cup member 34 and push rod 33 may be eliminated if desired by appropriate dimensioning of bushing i6 and the portion 38h of push rod 38. Spring 36 serves to take up any play between `the operating parts and provides a desirable operating feel but its use is not required.

I claim:

l. In a push-push operating mechanism, in combination, manually operable means including a reciprocably movable member, a movable fulcrum member normally biased to `a given position, an operating lever pivoted on said fulcrum, a wedge shaped lever engageable along one edge thereof with said reciprocably movable member and engaging along either of two other adjacent edges with said operating lever, said wedge shaped lever having bearing journals extending from opposite sides thereof, and means providing bearing recesses for each of said ybearing journals, said recesses being formed along one dimension to prevent any substantial axial movement of said bearing journals and along their other two transverse dimensions to provide four spaced apart bearing positions into which said bearing journals are moved in sequence as a result of two successive manual operations of said manually operable means.

2. The combination according to claim 1, wherein two of the bearing positions in each of said recesses have arcuate surfaces with which said bearing journals engage in sequence for pivotal movement thereon when moved from the other of the two remaining bearing positions.

3. The combination according to claim 2, wherein said arcuate surfaces lie adjacent each other on one side of said recess and said two remaining bearing positions are spaced apart from said two arcuate surfaces on the opposite side of the recess and are the at rest bearing positions for said bearing journals.

4. The combination according tto claim l, wherein a coil compression spring biases said fulcrum member, wherein the fulcrum is of inverted V-shape in cross section and the operating lever has two flat portions meeting at an obtuse angle and seats along the inner intersection line of said portions on the apex of said fulcrum member.

5. The combination according to claim 1, wherein the rst mentioned edge of said wedge shaped member is transverse to a line bisecting the angle between said two other adjacent edges thereof.

6. The combination according `to claim l, wherein said `manually operable means comprises a push rod having a pushbutton mounted on one end thereof `and a compression spring disposed between the other end of said push rod and said reciprocably movable member.

7. In a push-push operating mechanism, in combination, a member having an inverted V-shaped fulcrum portion, a spring normally biasing said member to a given position, an operating lever having two flat portions meeting at an obtuse angle and seating along the inner intersection line of such angle on the apex of said fulcrum portion, a wedge shaped lever engageable along either of two edges thereof, which intersect at an acute angle, with said flat portions of said operating lever on the side opposite from said fulcrum, said Wedge shaped lever having a third edge extending transversely of a line bisecting said acute angle and axially alined bearing journals extending from opposite sides thereof, means providing bearing recesses for each of said bearing journals, said recesses being formed along one dimension to prevent any substantial axial movement of said wedge shaped lever and being formed along the other two transverse dimensions to provide four spaced apart bearing positions for said bearing journals within each of said recesses with arcuate surfaces at two of such positions to facilitate pivotal movement of said wedge shaped lever on its bearing journals, and manual operating means comprising a push rod havcontact bearing est ing a pnshbutton mounted on one end thereof, a cylindrical cup-shaped member having its outer end engaging with said third edge of said wedge shaped lever, and a compression spring bearing at one end against a portion of said plush `rod adjacent the other end of the latter and bearing at its other end against the inner end of said cylindrical cup shaped member.

8. In a push-.push electric switch, in combination, a housing, manually operable means including a reciprocably movable member in said housing, a movable fulcrum member disposed within said housing, a spring normally biasing said fulcrum member to a given position, a contact operating lever pivoted on said fulcrurn `and having at least two contact carrying arms, stationary contacts mounted in said housing in line with said contact carrying arms, a driving lever having a wedge shaped portion which is engageable along its two intersecting edges with said contact operating levers, said driving lever also having bearing jo-urnals extending from opposite sides thereof, said housing having recesses formed lthereon for each of said bearing journals, said recesses being formed along one dimension to prevent any substantial axial movement of said bearing journals and formed along their other two transverse dimensions to provide four spaced apart bearing positions into which said bearing journals are moved in sequence as a result of two successive manual operations of said manually operable means.

9. The combination according to claim 8, wherein said housing comprises a molded insulating b-ase having a recess opening to one side within which said fulcrum member and bearing spring are mounted and in which said bearing recesses are formed, wherein said housing additionally comprises a cylindrical boss overlying said one side of said base and in which said reciprocably movable member slides.

l0. Thel combination according to claim 9, wherein said manually operable means further comprises a push rod reciprocably movable in said boss, a compression spring interposed between said reciprocably movable member and said push rod with said boss, and a pushbutton mounted on an end of said push rod exterior-ly of said boss.

l1. A push-push electric switch comprising a base having a recess closed at one side and opening to an opposite side thereof, a fulcrum member reciprocably movable in said recess, a spring biasing said member toward said opposite side of said base, a contact operating lever lhaving a portion bent at an obtuse angle intermediate its ends and pivotally mounted along the inner intersection line of said angle on the apex or" said fulcrum, said operating lever also having contact arms extending from one side of said bent portion of stationary contact members respectively mounted in said base in line with said contact arms, a driving lever having a wedge shaped portion engageable along the two intersecting edges thereof with said bent portions of said contact lever and alined bearing journals extending from the opposite sides thereof, said base having bearing recesses for said bearing journals opening into the first mentioned recess and formed in two transverse dimensions to provide four spaced apart bearing positions for said bearing journals, and means overlying said `open side of said base to close the same and including manually operable means comprising a reciprocably movable member engaged with a third edge of said driving lever and acting on two successive movements thereof in a direction opposite to that which said fulcrum member is biased to move said driving lever in sequence between said four bearing positions and when in two thereof to pivot it in reverse directions to cause pivoting of said contact lever in reverse directions to engage and disengage sai-d contact arms from said stationary contact member.

References Cited in the tile of this patent UNITED STATES PATENTS 2,044,065 Douglas lune 16, 1936

Images