US2350392A - Electric switch - Google Patents

Description

June 6, 1944. w. L, D N HAL 2,350,392

ELECTRIC SWITCH Filed June 23, 1941 Patented June 6, 1944 2,350,392 ELEGTRIQSWITCH William L. Dunn, Glenview, and Alexander W. Plensler, Berwyn, Ill.

Application June 23, 1941, Serial No. 399,258

3 Claims.

This invention relates generally to electrical switches and in particular to an electrical switch having rotary contact means adapted to be moved to circuit controlling positions by a step-by-step rotation thereof.

It is an object of this invention to provide an improved electrical switch.

Another object of this invention is to provide an improved rotary switch of step-by-step type.

A further object of this invention is to provide a rotary switch of step-by-step type in which progressive rotation is accomplished by a linear actuation of the switch operating button.

Another object of this invention is to provide a rotary switch of progressively actuated type, which is simple in design, rugged and compact in construction, easily manipulated by a straight pushing movement of the switch operating button, and readily adapted to function efiiciently for a plurality of applications.

A feature of this invention is found in the provision of a step-by-step operated electrical switch having a rotary contact unit rotatably.

supported for linear reciprocal movement, and including a ratchet wheel with teeth thereon for engaging stationary pawl elements, the pawl elements, during each reciprocal movement of the contact unit, selectively engaging each of the teeth in succession to rotate the contact unit a predetermined angular distance.

Another feature of this invention is found in the provision of a step-by-step operated switch having a rotary contact unit rotatably supported for reciprocal movement in a housing structure by means including a yieldable snap member, with the contact unit being linearly pushable in one direction against such yieldable member, and on release being linearly driven in an opposite direction by return of the yieldable snap member to a rest position, with rotation of a predetermined amount being accomplished during each reciprocal movement by coactingelements on the rotary contact unit and its housing structure.

A further feature of this invention is found in the provision of contact means for a rotary type switch in which the contact elements are of a construction adapted to precisely operate the circuits controlled by the switch.

Further objects, features, and advantages of this invention will become apparent from the following description when taken in connection with the accompanying drawing in which:

Fig. 1 is a sectional view of the complete switch assembly;

Fig. 2 is a sectional View as seen along the line 22 in Fig. 1;

Fig. 3 is a fragmentary sectional view taken along line 33 in Fig. 2, with parts of the rotary contact unit being shown therein in changed operating positions;

Fig. 4 is illustrated similarly to Fig. 3 showing the parts of the rotary contact unit in changed positions;

Fig. 5 is a top perspective view of the yieldable snap member adapted to linearly move the rotary control unit in one direction;

Fig. 6 is a sectional view taken along the line 6-6 in Fig. 1 looking toward the left as viewed in Fig. 1;

Fig. '7 is a sectional view on line l! in Fig. 1 looking toward the right as viewed in Fig. 1;

Fig. 8 is a sectional view of the contact elements as seen along the line 88 in Fig. '7; and

Fig. 9 is a modified form of the invention.

Referring to the drawing, the invention is illustrated in Fig. l as including a metal stamped housing or casing IU of cup-shape for a rotary contact unit designated generally as H. The

- housing In is restricted or of reduced section at its closed end 12 to provide an annular shoulder l3 therein for supporting a yieldable or snap member 14 (Figs. 1 and 5). The snap member I4 is of elongated and substantially flat form and arcuately curved transversely thereof to provide for a snapping action thereof when laterally deflected against such curvature. As shown in Fig. 1 the opposite ends l6 of the spring or snap member M are supported on the shoulder [3 with such member in a normal rest position being concavely bowed away from the shoulder. The central portion of the snap member I4 is thus unsupported so as to be laterally deflectible toward the closed housing end 12 for a purpose to be later fully explained.

The open end of the housing I0 is closed by an insulating terminal plate I! having angularly spaced peripheral recesses 18 for receiving corresponding lugs or ears 19 on the housing, the bending of the ears l9 inwardly of the housing and over the plate I1 securing the plate to the housing in an obvious manner. A tubular threaded bushing 21 for mounting the switch assembly is extended through the plate ll at a central aperture 22 formed therein. The mounting unit 2| is secured to the plate I! by the cooperating action of the shoulders 23 and 24 thereon, the shoulder 24 being formed by peaning or otherwise suitably bending the inner bushing end back against the plate l1. Contact terminals 26 mounted on the member.

tioned, includes an axis member 28 having a collar or bearing member 29 mounted near the end 3| thereof so that a portion of such end projects axially outwardly from the collar 29. Mounted on the axis 28 in a stacked relation and in; wardly of the collar 29 are a ratchet wheel 32, a metal spacing collar 34, an insulating washer 36,

contact means 31, and a second insulating washer 35, the assembly being retained on the axis by a C-shaped clamping or holding collar 38 (Fig. 7). The contact means 31 to be later fully described are suitably insulated from the axis 28. The projecting portion at the end 3| of the axis 28 is adapted to be received in an aperture 39 formed in the spring member 14, with the collar 29 bearing against the:convex side of the spring The opposite end 4! of. the axis 28 is guidably supported within the mounting unit 2! and extends outwardly therefrom, and serves as the operating button for the switch assembly. Thus from a consideration of Fig. 1 it is seen that movement of the axis 28 axially toward the right linearly moves the rotary control unit toward the right, as also viewed in Fig. l, and deflects the snap member 14 toward the closed end 12 ofthe housing Ill. On release of the axis 28 the rotary control unit His returned to its position'shown in Fig. 1 by the return of the spring member 14 to its normal rest position. A reciprocal movement of the rotary control unit is thus Fig. 1. As previously mentioned, the pawl 43 is adapted to be received between adjacent teeth 42. Thus as is clearly shown in Fig. 3, when the axis 28 is in its normal idle position, as defined by the rest position of the snap member I 4, the pawl 43 extends into an engaging position between the teeth 42b and 420 to retain the contact unit H stationary. As the axis 28 is linearly pushed at the operating end 4l inwardly of the casing H1, or to the right as viewed in Fig. 1, the pawl 43 passes between the adjacent teeth 42b and 420, with the movement of the teeth 42b and 420 and hence of the contact unit H being linear until the tooth 42b slidably engages the cam surface 48 on the pawl element 44.

- When this engagement occurs the tooth 42b folaccomplished-each time the axis member 28 is linearly pushed inwardly of the housing III.

A progressive'or step-by-step rotation of the rotary control unit H and hence of the contact means 31 (Fig. 6) across the terminals 26 on the terminal plate I1 is accomplished by the provision of means including the ratchet wheel 32. The wheel 32 is formed on the periphery thereof with radially projecting extensions or teeth 42 for engaging pawl orcam elements 43 and 44 (Fig. 2) mounted on the inside'wa'll of. the housing I 0.- As is best shown in Fig. i 2, the pawl elements 43 and 44 are integrally formed with a mounting portion 46 which may be riveted or welded to the housing. The pawl elements 43 and 44 are extended inwardly of the housing l0 andprovided with corresponding lateral projections 41 and 48, respectively, spaced from each other longitudinally of the housing and having cam surfaces 49 and 5|, respectively, arranged in'a substantially normal relation (Figs. 1-3) Thepawls 43 and 44 and their corresponding cam portions 41 and 48 are of a size adapted to be received between adjacent teeth or extensions 42 on the wheel 32 fora purpose to be later noted.

In the operation ofthe switch assembly assume three of the teeth 42, designated as 42a,- 42b, and 420 for clarity'of description.- to be in the positions relative to the pawls 43. and 44 shown in Fig. 3. It is to be understood, of course, that the operation of the switch assembly is the same for all of the teeth on the wheel 32. position of the teeth 42a42c corresponds to the position of the rotary contact unit ll shown in This ,6), the rotary contact pairs of angularly spaced contact elements5l and lowsthe cam surface 48 to initially rotate the j contact unit II, the tooth 42a during this initial rotation being moved 44, as shown in Fig. 3. tinues until the member deflected position toward the closed end l2 of the housing I0. On release of the axis 28 and dur ing the return thereof to its idle position shown in Fig. 1 by the snapping action of the snap member l4 to a rest position, the tooth 42b is moved toward the left as viewed in Fig. 3 into slidable engagement with the cam surface 41 on the pawl element 43. additional'rotation of the contact unit H the tooth 42a during this additional rotation, being moved adjacent the pawl 43. As the axis 28 ap proaches itsidleposition, the tooth 42b is moved out of engagement with the cam surface 41 to provide for the pawl 43 being received between the teeth 42a and 42b as shown in Fig. 4. This position of the pawl 43 between the teeth 42a and adjacent the pawl element This initial rotation con- |4 snaps into a laterally 42b and in an engaging position therewith, defines the extent of rotation of the contact unit II.

From a consideration of Figs. 3 and 4, therefore,

axis 28 and hence the As previously mentioned, the terminal plate IT is provided with-three contact terminals 26 (Fig. means 37 having four 52 and the ratchet wheel 32 twelve teeth (Fig. 7). This relative construction of the contact terminals and elements and of the ratchet wheel 32 provides for three control positions of the switch assembly with the cycle of these three positions being repeated four times during each complete revolution of the contact unit II. It is obvious, of course, that these parts may be relatively changed to adapt the switch assembly for application'to other desired control operations.

With'reference to Figs. 7 and 8, it is seen that paired elements 5! and 52 are angularly spaced relative to each other and displaced axially of :the axis 28. Corresponding elements 5| are integrally connected to a hub portion 53, with the elements 52 being similarly connected to'a hub portion 54, the elements and associated hub portions being formed from a single piece of conductor material as by stamping or a like machining operation. Each contact element 5| and 52 includes a. radially extendin portion 56 and a peripheral portion 51 connected at one end thereto. As shown in Fig. 8, each peripheral portion is of substantially arcuate contour so that only the This engagement provides for an,

the reciprocal movement free end 58 thereof is engageable with the stationary terminals 26. With'rotation of the'contact means 31, therefore, in the direction indicated by the arrow in Fig. 8, the free ends 58 lag the connected ends of the peripheral portions in passing over the terminals 26. As illustrated, the free ends 58 for each pair of contact elements and 52 are spaced an angular distance apart corresponding substantially to the spacing of the teeth 42 on the wheel 32 so that engagement of a pair of elements and a terminal 25 is maintained for a rotation of the contact unit ll through a distance corresponding substantially to such tooth spacing. By virtue of this construction and assembly of the contact elements 5| and 52 a precise control operation of the circuits (not shown) connected to the terminals 26 is accomplished.

A modified form of the invention is shown in Fig. 9, which is substantially similar in all respects to the above described assembly of Fig. 1, except for the relative assembly of the axis of the contact unit H with the snap member l4. Thus as shown in Fig, 9 the axis 28' is of a reduced section at its end 3| with such end being formed with an axial bore M for guidably receiving a pin or stub shaft 52 mounted in the closed end I! of the housing "I, the pin 62 being extended through the aperture 38 in the snap member M. It is apparent, therefore, that the axis 28' at its end 3| rests entirely on the convex side of the snap member I and is retained for rotatable support thereon by the insertion of the pin 62 within the bore Bl. The operation of this modification is the same in all respects to the operation of the switch assembly shown in Fig. 1 so that a further description thereof is believed to be unnecessary.

From a consideration of the above description and the drawing, it is seen that the invention provides an improved switch assembly having a rotary contact unit which is adapted to be operatcd step-by-step or progressively rotated in response to a. linear or straight pushin movement of the axis 28 or operating button for the switch. The complete assembl i comprised of but a minimum of easily machined and assembled parts and is readily adapted to operate efliciently for a plurality of applications.

Although the invention has been described with reference to a specific embodiment thereof, it is to be understood that it is not to be so limited, since the parts thereof may be relatively changed or modified within the full scope of this invention as defined by the appended claims.

We claim:

1. In a switch having frame means and circuit switching means, the combination including a rotary unit mounted on the frame means, an axially moving member connected with said rotary unit and depressible from an idle position, spring means acting to return in one direction said moving member and rotary unit to idle position after the depressing of the same in the opposite direction, said rotary unit including a ratchet wheel with a plurality of angularly and equally spaced extensions thereon, and a pair of pawls mounted on said frame means, each pawl having a portion extending radially relative to the rotary unit axis and toward said axis with said radial portions being spaced apart in a direction longitudinally of said axis, and each said pawl radial-portion having a cam-faced portion extending substantially at right angles to the corresponding pawl portion, and said cam-faced portion having a cam face thereon and said two cam-faced portions extending toward one another, with said ratchet wheel extensions and said pawls being so constructed and arranged that two adjacent extensions-straddle a pawlradial-portion when the switch isin idle position, and one of said two extensions acts upon both cam faces in a complete reciprocation of said moving member in said two opposite directions to rotate said rotary unit to a position such that one of said two extensions and an adjacent third extension straddle said radial portion in the next succeeding rotary position of said control unit to said first mentioned idle position.

2. In a switch having frame means and circuit switching means, the combination including a rotary unit mounted on the frame means, an axially moving member connected with said rotary unit and depressible from an idle position, spring means acting to return in one direction said moving member and rotary unit to idle position after the depressing of the same in the opposite direction, said rotary unit including a ratchet wheel with a plurality of circumferentiall and equally spaced extensions thereon, and a pair of stationary pawls on said frame means, each having a portion extending radially relative to the rotary unit axis and toward said axis with said radial portions being spaced apart in a direction longitudinally of said axis, and each pawl having a cam portion thereon, with said ratchet wheel extensions and said pawls being so constructed and arranged that two adjacent extensions straddle a pawl-radial-portion when the switch is in idle position, and one of said two extensions acts upon both cam portions in a complete reciprocation of said moving member in said two opposite directions to rotate said rotary unit to a position such that one of said two extensions and an adjacent third extension straddle said radial portion in the next succeeding rotary position of said control unit to said first mentioned idle position with said spring means comprising an elongated bowed member mounted at the outer ends thereof on said frame means and having an aperture centrally thereof, and said rotary unit including an axial extension on one end seated in said aperture.

3. In a switch having frame means and circuit switching means, the combination including a rotary unit mounted on the frame means, an axially moving member connected with said rotary unit and depressible from an idle position, spring means acting to return in one direction said moving member and rotary unit to idle position after the depressing of the same in the op site direction, said rotary unit including a ratchet wheel with a pluralit of circumferentially and equally spaced extensions thereon, and a pair of stationary pawls on said frame means, each having a portion extending radially relative to the rotary unit axis and toward said axis with said radial portions being spaced apart in a direction longitudinally of said axis, and each pawl having a cam portion thereon, with said ratchet wheel extensions and said pawls being so constructed and arranged that two adjacent extensions straddle a pawl-radial-portion when the switch is in idle position, and one of said two extensions acts upon both cam portions in a complete reciprocation of said moving member in said two opposite directions to rotate said rotary unit to a position such that one of said two extensions and anadjacent third extension straddle sa'id radial portioni'n-the next succeeding rotary position-of saidcontroi' unit to'said first mentioned idle positionlwith said frame means including a housing having an apertured bottom, said spring means having a central aperture and beingsupported at its outer ends on said housing, with said rotary unit having a bore centraily thereof extending from the bottom end thereof, and means for centering said rotary unit includingan axis pin extending through the housing bottom aperture and said spring aperture 5 and into said bore.

WILLIAM L. DUNN. ALEXANDER W. PLENSLER.

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