US 3350521 A
Abstract available in
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Description (OCR text may contain errors)
Oct. 31, 1967 H. w. BROWN 3,3 0,
MINIATURE SWITCHES OF THE ROCKING CONTACT TYPE Filed Dec. 5, 1964 I 5 Sheets-Sheet l 31, 1967 H. w. BROWN 3,350,521
MINIATURE SWITCHES OF THE ROCKING CONTACT TYPE Filed D90. 5, 1964 5 Sheets-Sheet 2 Oct. 31, 1967 H. w. BROWN 3,350,521
MINIATURE SWITCHES OF THE ROCKING CONTACT TYPE Fil'ed Dec. 5, 1964 3 Sheets-Sheet 3 3,350,521 MINIATURE SWITCHES OF THE ROCKING CONTACT TYPE Harry W.'Brown, Big Bend, Wis., assignor to Cutler- Hammer, Inc., Milwaukee, Wis., a corporation of Delaware Filed Dec. 3, 1964, Ser. No. 415,676 7 Claims. (Cl. 200-67) This invention relates to miniature switches and more particularlyto miniature switches of the manually operable type. I
While not limited thereto, the invention is especially applicable to miniature switches of the toggle lever actuated type.
' An object of the invention is to provide improved miniature switches.
A more'specific object of the invention is to provide improved switch structure which adapts it for miniaturization and affords superior mechanical and electrical characteristics.
Another specific object of the invention is to provide an improved single pole toggle lever switch especially adapted for miniaturization.
Another specific object of the inventionis' to provide an improved double pole toggle leverswitch especially adapted for miniaturization.
Other objects and advantages of the invention will hereinafter appear. These and other objects and advantages of the invention and the manner of obtaining them will best be understood by reference to'the following description of embodiments thereof taken in conjunction with-the accompanying drawings, wherein:
FIGURE 1' is an isometric view of a single pole toggle lever switch constructed in accordance with the invention;
FIG. 2 is an enlarged cross-sectional viewof the switch of FIG. 1 taken along line 2-2 of 'FIG.3;
FIG. 3 is a view partly in section taken along line 3-3 of FIG. 2;'
FIG. 4 is an exploded isometric view of the parts of the switch'of FIGS. 1-3;
FIG. 5 is an isometric view of a double pole toggle lever switch constructed in accordance with the invention; a
FIG. 6 is an enlarged cross-sectional view of FIG. 5 taken along line 6-6 of FIG. 7; 7
FIG. 7 is a view partly in section taken along line 7-7 of FIG. 6;
FIG. 8 shows a front elevational view of'the actuator of the switch of FIGS. 5-7; I
of the switch and FIG. shows an exploded isometric view of the parts of the switch of FIGS. 5-9.
Referring to FIGS. 1-4, there are shown thephysical characteristics of a single-pole double-throw, toggle lever FIG. 9 showsa top view of the actuator of FIG. 8;
3,350,521 Patented Oct. 31, 1967 top being open. The open sides of the base portions face one another with the edges of the end walls and bottom walls thereof abutting and are clamped in this position by 2 switch frame 6 which also covers the open top of the ase.
As shown in the exploded view in FIG. 4, the bottom of each base portion 2 is provided with three spaced notches or apertures including a center aperture 2a and relatively narrow apertures 2b on either side thereof. The three apertures in the opposite base portions are respectively in alinement with and connect with each other for clamping a contact support terminal 8 in the central aperture and for clamping contact terminals 10 and 11 in the side apertures. The side wall is provided with three vertical grooves including a groove 20 opposite aperture 2a and relatively narrow grooves 2d opposite apertures 2b for anchoring lateral projections of the contact terminals. These contact terminals 10 and 11 are provided with a generally T-shaped upper end or contact portion and the ends of the cross on the T constitute the lateral projections 10a and 11a which enter the narrow grooves 2d. The relatively wider center groove 20 is provided to anchor contact support terminals of the type hereinafter described in connection with FIGS. 5-10.
Contact terminals 10 and 11 shown in FIG. 4 are provided with slots 10b and 11b in opposite edges thereof at about the midportion which pass through the apertures in the bottom of the base for securely fixing the contact terminals to the base when the two halves thereof are clamped together. Contact terminals 10 and 11 are similar to one another except that the latter has a higher contact portion as shown in FIG. 2 to provide momentary-on switch operation. Contact support terminal 8 is provided with similar slots 8a in opposite edges thereof for fixing the same in the center aperture 2a between the base halves. As shown in FIG. 2, contact support terminal 8 is formed of a metal strap bent double in the middle and having its ends bent outwardly and then upwardly to form a supporting cradle for movable contactor 12. The opposite sides of such cradle, that is, the ends of the metal strap are provided with slots 8b to allow rocking of the movable, contactor thereon. While terminal -8 is preferably made from a single strap, it could be made of two pieces not connected at the lower ends.
Movable contactor 12 is a metal strap having lateral extensions 12a on opposite edges at its midportion for retaining it in the cradle of the contact support terminal 8. Contactor 12 also is suitably bent at its middle so that the two halves thereof are at upward angles and are separated from-contact terminals 10 and 11 when, the switch 'is in its off position as shown in FIG. 2. V Actuator 14 has a generally V-shaped runner with a flat horizontal upper surface which is provided with a hole f'orreceiving the reduced lower end portion 16a .of a plunger pin 16. The lower runner portion of actuator 14 is reduced in thickness so that it can be freely moved rounded enlarged, portion 18a near its lower end for pivotally supporting it in bushing 22. For this purpose, the
upper end of the hole in bushing 22 is provided with a constriction formed by an internal rib 22a against which the enlarged portion of the operating lever bears under the force of spring 20 and on which it pivots upon movement of the operating lever. Bushing 22 is threaded on the outside and is provided with a keyway 22b to facilitate mounting of the switch in an aperture in a panel. Bushing 22 is rigidly secured at its lower end into a central hole in switch frame 6 as by peening a thinned end of the bushing against the inner edge of the hole as shown in FIG. 2.
Switch frame 6 is a sheet metal punching in the shape of a strap but having side flaps 6a on opposite sides of its midportion formed by bending lateral portions thereof downwardly. The upper portions of the two halves of switch base 2 snugly fit between these flaps and are held together thereby. The opposite end portions of the switch frame 6 are bent downwardly along the ends of the base and are provided with pairs of lateral ears 6b which may be bent around the corners of the base and against the opposite sides thereof as shown in FIG. 1. As shown in FIGS. 1, 3 and 4, each base portion is provided on its outer side with a depression at the top for receiving the corresponding side flap 6a and a pair of depressions at its lower corners for receiving lateral ears 6b of the switch frame.
The double-pole modifications shown in FIGS. -10 uses some parts like those in the single-pole switch hereinbefore described and these parts have been given like reference characters. However, it is apparent that the base has an added part to provide two cavities or compartments for the two poles of the switch. A double actuator also is used and the switch frame is wider to encompass the thicker base.
As shown in FIGS. 5 and 10, a central base portion 24 is placed between like base portions 2, the latter being identical to those used in the single pole switch. The central base portion 24 has two end walls, a bottom wall and a dividing wall upstanding from the bottom. This dividing wall is only about one-half the height of the end walls since the actuator must extend thereover to engage both movable contactors. As shown in FIG. 10, the bottom of base portion 24 is provided on opposite sides of the dividing wall with center notches or apertures 24a and relatively narrow notches or apertures 24b on opposite sides thereof for receiving contact support terminal 26 and contact terminals 10 and 28. As will be apparent, these apertures in the central base portion are respectively in alinement with apertures 2a and 2b in base portions 2 whereby to clamp the contact terminals therebetween. Central base portion 24 is also provided with vertical grooves 240 and 24d on opposite surfaces of the dividing wall for receiving and anchoring the lateral projections such as 10a and 28a of the stationary contacts.
It will be recalled that the single pole switch in FIGS. 1-4 was illustrated and described as having a cradle type of center contact support terminal 8. This cradle provides a center off position and can be used in either the single-pole or double-pole switch. To show a variatlon in switch operation, the double-pole switch in FIGS. 5-10 has been illustrated as having a flat contact support terminal 26 which is used when a center position for the operating lever is not desired. This double-pole switch is illustrated as having an on position on one side and a momentary on position on the other side and no center off position. For this purpose, contact support terminal 26 is thicker than the other contact terminals 10 and 28 on either side thereof but is flat. It is provided with slots 26a on opposite edges at its midportion whereby it is gripped by base portions 2 and 24. Its upper end is provided with a slot 26b for receiving a modified movable contactor 30 for rocking movement thereon. Movable contactor 30 is in the form of a metal strap having two pairs of lateral projections 30a spaced from one another to provide side slots therebetween. As will be apparent, the
narrow portion of contact 30 between the pairs of projections enters into slot 26b in contact support 26 and the pairs of projections retain it thereon. The slots between the pairs of projections 30a are wider than the thickness of contact support terminal 26 to allow the contactor to rock freely thereon.
Contact terminal 28 is like contact terminal 10 except that the upper contact portion thereof is higher. Since the pivot point of the movable contactor is higher in FIG. 6 than it is in FIG. 2 to avoid a center off position, the stationary contact 28 must also be higher to provide for momentary action, that is, to cause reopening of the switch when the operating lever is released.
As shown in FIGS. 8-10, actuator 32 is designed to straddle the dividing wall in the base and is provided with a pair of generally V-shaped runners 32a for sliding along the respective movable contactors 30, these runners being connected by a horizontal flat portion extending across the dividing wall. The vertical hole in the center of actuator 32 is elongated or oval in shape as shown in FIG. 9 to allow the actuator to rock a limited amount on the reduced lower end portion 16a of pin 16 as depicted by dotted lines in FIG. 8. Also, a pair of rounded beads 32b are molded on the upper surface of the actuator, one on each side of the hole and immediately adjacent thereto. These beads bear against the shoulder on pin 16 to facilitate rocking of the actuator on the pin. As will be apparent, this rocking allowance of the actuator insures positive pressure engagement thereof against both movable contactors under the force of the compression spring which is inside the operating lever. This pressure engagement insures closing of the contacts and avoids any condition where one pole closes and the other pole is held open due to binding of the parts.
Switch frame 34 is similar to that in FIGS. l-4 except that it is wider to embrace and cover the thicker base in the double-pole switch.
While the single-pole switch of FIGS. 1-4 has been illustrated as having on and momentary on operating positions and a center off position and the doublepole switch of FIGS. 5-10 has been shown as having on and momentary on operating positions with no center position, it will be apparent that other combinations of operating positions are possible. Any combination of on, momentary on, off and center none positions may be provided by selecting proper contact terminals and central contact support terminals of the type shown in FIGS. 4 and 10 and by selecting a suitably bent movable contactor to fit the center contact support terminal used in each particular case.
The switches hereinbefore described are constructed so that they are especially adapted for miniaturization. For example, these switches can be constructed so that they are only about 1% inches high overall. The singlepole switch at its frame may be only about one half inch long and a quarter inch wide. The double-pole switch at its frame may also be only about a half inch long and slightly less than a half inch wide. These small dimensions provide a switch that has a capacity of 5 amperes at volts alternating current.
The characteristics which afford the aforementioned miniaturization and electrical capacity reside in the structural features and the combination thereof hereinbefore illustrated and described. For example, the contact terminals and the contact support terminals are capable of carrying a large current relative to their size since no rivets are required to connect the contact portions thereof to their external terminal portions. This is brought about by the shape and arrangement thereof whereby the contact terminals and contact support terminals are clamped between portions of the insulating base. The elimination of riveting in contact support terminal 8 is derived from its bent-double structure whereby a cradle for the movable contractor is provided by a forming operation alone. The arrangement of the actuator, pin and operating lever and spring therein of both the single-pole and doublepole switches provides operating means of minimum height for a toggle lever switch while also affording sufficient contact pressure when the contacts are closed. The symmetrical construction of the base and the design of switch frame which holds all of the parts together further, contribute to the advantageous features hereinbefore described.
While the invention hereinbefore described is effectively adapted to fulfill the objects stated, it is to be understood that I do not intend to confine my invention to the particular preferred embodiments of miniature switches disclosed, inasmuch as they are susceptible of various modifications without departing from the scope of the appended claims.
1. In an electric switch especially adapted for miniaturization:
a housing provided with a contact cavity;
a pair of spaced stationary contacts in said cavity and having terminal portions extending through a wall of the housing;
a movable contact arranged to be rocked in opposite directions to engage at either end portion thereof one or the other of said stationary contacts;
actuator means for rocking said movable contact;
and means for performing the combined functions of supporting said movable contact for rocking movement and forming a common connector arranged to be electrically connected to either one of said stationary contacts when said movable contact is rocked without use of connecting means such as rivets or the like;
said means comprising current conducting strips lying flat against one another for a portion of their length and extending through a wall of the housing to provide an external terminal;
the portions of said strips within the housing cavity being bent away from one another and then bent parallel to one another and to the first portions thereof and being formed to provide a cradle for said movable contact.
2. The invention defined in claim 1, wherein said parallel portions are provided with notches for receiving said movable contact.
3. In an electric switch especially adapted for miniaturization:
an insulating housing formed of at least two complementary portions to provide a contact cavity therein;
a pair of spaced stationary contacts formed of flat strips gripped in slots between said housing portions to provide contact portions in said cavity and terminal portions outside the housing;
a movable contact arranged to be rocked in opposite directions to engage at either end thereof one or the other of said stationary contacts;
actuator means for rocking said movable contact;
and means for performing the combined functions of supporting said movable contact for rocking movement and forming a common connector comprising:
a current conductor strip folded at its middle and having its end portions bent away from one another and then bent parallel to the folded portion to extend in a direction away from the latter thereby to form a substantially U-shaped cradle the tips of which have cut-out portions for receiving said movable contact within said cavity and said folded portion extending outside the housing to provide a terminal, said current conductor strip being aunitary member capable of carrying a large current for its small size since it does not require rivet holes or the like;
and said movable contact being provided with lateral projections extending between the legs of said U- shaped cradle to retain the movable contact therein but to permit rocking to engage either one of said stationary contacts.
4. In a miniature electric switch adapted to carry a relatively large currentfor its small size:
an insulating housing formed of two symmetrical,
complementary portions abutting one another to provide a compartment therein open at the top and having alined notches in the abutting portions of the bottom forming apertures therethrough;
at least two spaced stationary contact-terminals formed of flat strips clamped in said notches between said housing portions to provide contacts in said compartment and integral terminals outside the housing;
a movable contact arranged to be rocked in opposite directions within said compartment to engage one of said stationary contacts;
means on the other stationary contact for pivotally supporting said movable contact for said rocking movement comprising layers of said other stationary contact bent apart to form a cradle for said movable contact, said cradle and integral external terminal being a unitary member performing the combined functions of supporting said movable contact and forming an external connector;
and means for rocking said movable contact comprisan actuator slidable on said movable contact;
a manually operable toggle lever;
and a spring biased plunger pin at the lower end of said toggle lever having a reduced end portion extending into a hole in said actuator;
and a switch frame clamping said housing portions together and including a bushing in which said toggle lever is pivotally supported.
5. The invention defined in claim 4, wherein:
said housing comprises grooves on the interior walls thereof adapted to receive contact-terminals of different heights;
and lateral projections on said contact-terminals anchored in said grooves.
6. In a miniature electric switch constructed so that it will have a relatively large current capacity for its small size:
an insulating housing formed of two symmetrical outer portions abutting opposite sides of a center portion, said center portion having a dividing wall forming two compartments open at the top and open into one another above said dividing wall, said portions having alined notches in the abutting portions of the bottom;
stationary contact-terminals clamped in said notches between said housing portions to provide contacts in said compartments and respectively integral terminals outside the housing; movable contacts arranged to be rocked in opposite directions within the respective compartments to engage a stationary contact in each said compartment;
means on the other stationary contacts in the respective compartments for pivotally supporting the respective movable contacts for rocking movement comprising two layers of which each said other stationary contact is formed and being bent outwardly and then upwardly to form a seat for rockably supporting the associated movable contact, said seat and integral terminal being a unitary device requiring no rivets or the like which would reduce its current capacity;
and means for rocking said movable contacts comprisan actuator straddling said dividing wall and having depending runners slidable on said movable contacts;
a manually operable toggle lever having a bore therein opening at its lower end;
a spring biased plunger pin extending from said bore and having a reduced end portion;
and a hole in said actuator for said reduced end portion of said pin and being larger than the latter but smaller than the remainder of said pin whereby the shoulder on said pin bears against said actuator and the latter is freely rockable a limited amount to insure pressure engagement with both movable contacts.
7. The invention defined in claim 6, wherein said actuator comprises:
rounded beads in its upper surface on opposite sides of saidv hole and bearing against the shoulder of said pin to enhance rocking of said actuator on said shoulder.
References Cited UNITED STATES PATENTS Meuer 20068 X Dietrich 20068 Obszarny 200--68,X Lauder et a1.
Heusser 200-68 Ludwig. Anderson.
ROBERT K. SCI-IAEFER, Primary Examiner.
D. SMITH, JR., Assistant Examiner.