Rocker Switch With Integral Off Lock

Integral and non-integral off locks for electric switches have been known heretofore. In one form, a trigger switch is provided with a spring-biased latch lever carried by the trigger that locks onto a small round hole in the switch frame whenever the trigger returns to "off" position. And a release button must be pressed to release this lever to allow the trigger to be operated. In another known form of the non-integral type, a trigger, a spring-biased latch and a removable release key are separately mounted in the tool handle. This spring-biased latch moves into the path of the trigger to prevent operation thereof, and the key must be depressed to pivot this latch out of the path of trigger travel to allow operation thereof. This key can be removed to lock the switch "off". In still another known form, a rocker switch is provided with an integral off lock such that removal of a key from a hole in the rocker decouples the rocker button for lost motion movement relative to the contact actuator to prevent switch operation. Insertion of the key couples the rocker to the contact actuator to afford normal switch "on" operation. One-way interference between the rocker and contact actuator affords actuation of the switch "off" even when the key is out.

While these prior off lock designs have been useful for their intended purposes, they nevertheless have had certain disadvantages. For example, the first mentioned form is not readily adaptable for use in rocker switches. The second mentioned form is not self-contained and thus requires that individual parts must be mounted in the tool handle. The third mentioned form can be rather easily defeated when the key is removed by inserting a stiff wire into the hole in the rocker and pressing the contact actuator to its "on" position.

Accordingly, it has been found desirable to provide a rocker switch with integral off lock that overcomes disadvantages of the aforementioned type.

This invention relates to rocker switches and more particularly to rocker switches with integral off lock.

An object of the invention is to provide an improved rocker switch.

A more specific object of the invention is to provide a rocker switch with an improved slidable off lock.

Another specific object of the invention is to provide a rocker switch with an improved off lock that is self-contained in that the slidable lock lever is carried by the contact actuator.

Another specific object of the invention is to provide a rocker switch with an improved off lock including a spring-biased lock lever that is longitudinally reciprocal.

Another specific object of the invention is to provide an improved rocker switch with an integral off lock having a minimum number of parts that are easily assembled.

Another specific object of the invention is to provide a rocker switch with an improved off lock having a removable rocker button key and a lock lever that is inaccessible to anything other than such key and that is not easily defeated when the key is removed.

Other objects and advantages of the invention will hereinafter appear.

FIG. 1 is an enlarged cross-sectional view of a doublepole rocker switch with integral off lock showing the rocker button key snap-on legs in elevation;

FIG. 2 is a further enlarged cross-sectional view of the rocker button showing the off lock lever in its retracted position;

FIG. 3 is an exploded cross-sectional view like FIG. 2 but showing the rocker button key separated from the contact actuator and showing the off lock lever in its extended position;

FIG. 4 is a lateral cross-sectional view taken along line 4--4 of FIG. 2 to show the interfitting elements of the parts;

FIG. 5 is a lateral cross-sectional view taken through the center of the rocker button and contact actuator of FIG. 2 to show internal details;

FIG. 6 is a horizontal cross-sectional view taken along line 6--6 of FIG. 2 to show the lock lever in top view;

FIG. 7 is a lateral cross-sectional view taken along line 7--7 of FIG. 2 to show the lock release projection of the rocker button key; and

FIG. 8 is an internal view of one of the contact actuator halves showing an alternative form of off lock lever.

Referring to FIG. 1, there is shown a rocker switch with integral off lock constructed in accordance with the invention. As shown generally therein, the rocker switch is provided with a housing comprising an insulating base 2 and a metal frame 4. This base is a generally rectangular cup closed at the top by the frame which pivotally supports a rocker assembly 6 hereinafter described. The frame could be molded insulating material.

Base 2 is provided with means for supporting stationary and movable contacts. For this purpose, the flat bottom of the base is provided with a plurality of round holes 2a, for example, four holes for the double-pole single-throw switch illustrated, through which rivets extend to connect internal stationary contacts to external terminals. As shown in FIG. 1, there is a left end contact 8 connected by a rivet 10 to an external terminal 12. And there is a central stationary contact 20 connected by a rivet 22 to an external terminal 24. Left end stationary contact 8 is in the form of a flat coined element similar to a rivet head whereas central stationary contact 20 is in the form of a stationary cradle for rockably supporting a two-position movable bridging contact 26 in a manner well known in the art. A similar set of contacts is provided for the other pole of the switch.

Frame 4 has a plurality of depending legs 4a that embrace the ends of the base and their lower ends are bent inwardly into undercut notches 2b to secure the frame to the base. Frame 4 has a flat upper surface 4b overlying the base with a generally rectangular hole 4c centrally therein through which rocker assembly 6 extends into the base for actuation of the contacts. Frame 4 additionally has left and right upwardly and outwardly turned arms 4d and 4e, respectively, as shown in FIG. 1, each having a threaded hole or other suitable means for mounting the switch to a mounting panel. Furthermore, frame 4 has rocker assembly supporting means including a pair of spaced, upstanding, generally triangular, bent-up portions 4f and 4g having aligned holes therethrough for a pivot pin 27 that supports the rocker assembly as shown in FIGS. 1-3 and 5.

Rocker assembly 6 consists of four parts in the version shown in FIGS. 1-7 and five parts in the version shown in FIG. 8. Thus, in the first mentioned version, this rocker assembly consists of two like contact actuator halves 28 and 30 of molded insulating material, a lock lever 32 confined therebetween for limited movement, and a snap-on rocker button 34 that also serves as the key for releasing the off lock. Alternatively, the off lock release key may be of any other shape or may form only a small part of the rocker button face.

These contact actuator halves are provided with means for operating the respective movable contacts such as contact 26. For this purpose, each contact actuator half is provided with a bore 28a, 30a shown in FIG. 5 extending up from its lower, reduced end portion for retaining a spring biased plunger 36 as shown in FIGS. 1 and 6 which plunger slides along and rockably actuates the respective on-off movable contact when the rocker assembly is actuated. Springs 38 bias these plungers downwardly.

These contact actuator halves are also provided therebetween with a guiding slot allowing limited reciprocal movement of the lock lever and the latter is provided with a suitable configuration to cooperate therewith. For this purpose, as shown in FIGS. 2 and 3, molded insulating lock lever 32 is provided at its left end with an angular cam surface 32a which cams itself momentarily in to snap below the housing when the contact actuator assembly is pivoted counter-clockwise while the rocker button key is removed as in FIG. 3. The lock lever is also provided with a pair of lateral wings 32b having cam surfaces thereon for engagement by complementary cam surfaces 34a on projections 34b of the rocker button key 34. These wings are suitably spaced from upper and lower stop projections 32c on this lock lever so that they are positioned within slots 28b, 30b in the contact actuator halves that receive projections 34b of the button key. As shown in FIGS. 3 and 5, the guiding slot for the lock lever is provided with a constriction 28c, 30c forming a stop for upper and lower projections 32c of the lock lever to limit the leftward movement of the latter. The right end of the lock lever is provided with a thin section 32d that is bent double in the cavity within the contact actuator halves to serve as a compression spring biasing the lock lever into its leftward extended position in FIG. 3. Thus, there is provided an integral bias spring molded in one piece with the lock lever of plastic material such as "Celcon M90" or "Zytel" or the like. The extreme end 32e of this spring 32d is T-shaped for good abutting engagement with the righthand wall of the cavity, as shown in FIGS. 3 and 6, spanning the hole thereat provided by the symmetrical contact actuator halves. The movement of this lock lever is limited in its leftward extended direction by projections 32c abutting constriction walls 28c, 30c. The movement of this lock lever is limited in its rightward retracted direction by integral spring 32d which keeps it from going further than it is forced by cams 34a and projections 34b of the rocker button key.

These two contact actuator halves 28 and 30 are kept in registration with one another by a plurality of suitable projections 28d and 30d fitting snugly into complementary recesses such as 30e in the opposite half, as shown in FIGS. 2-4. With such interfitting engagement, the two contact actuator halves are then held snugly between upstanding portions 4f and 4g of the frame with headed pivot pin 27 passing therethrough and flared at its other end to support the same for pivotal movement.

Rocker button 34 serves not only as the manually engagable part for actuating the switch but also as the removable key leaving the switch locked in its off position. For this purpose, this rocker button key is provided with the aforementioned projection 34b having cam 34a at its divided end for withdrawing the lock lever into the contact actuator when this key is snapped in place. This rocker button key is also provided with the usual finger engaging portion including a laterally V-grooved shallow V-shaped upper surface 34c facilitating rocking thereof by pressing on the high end. In addition, this rocker button key is provided with snap-on means coupling it removably on the pair of contact actuator halves. This means comprises two pairs of inwardly detented resilient legs 34d shown most clearly in FIGS. 1, 3, 4 and 6. The two legs of the first pair thereof are symmetrically spaced on the front of contact actuator 28 and the two legs of the other pair thereof are symmetrically spaced on the back of contact actuator 30. The front and rear walls of the contact actuators are provided with complementary grooves having deeper portions at their lower ends for the detents on legs 34d thereby to afford snap-on retention of the rocker button key on the contact actuators as well as snap-out removal when desired. While a V-shaped rocker surface is shown, other finger-engaging shapes such as a paddle or the like are possible.

As shown in FIGs. 6 and 7, projection 34b of the rocker button key is bifurcated at its lower end so that its two cams 34a engage wings 32b equally and smoothly retract the lock lever within the contact actuator when the rocker button key is snapped in place. While two cams on each of the key and lock lever are shown, it will be apparent that one or more may be used.

The modification in FIG. 8 differs only in the spring for the lock lever. Thus, a modified lock lever 40 is provided that differs from that hereinbefore described in that thin section spring 32d has been omitted and only a short stud 40a left in place of it to serve as a retainer for one end of a separate helical compression spring 42 confined between the righthand end of the lock lever and a plug 44 that closes the hole in the wall of the cavity within the contact actuator halves. This spring is in compression to bias lock lever 40 to its extended position as shown in FIG. 8. Upon insertion of the rocker button key, the lock lever is cammed longitudinally to its retracted position against the force of compression spring 42. Alternatively, the hole in the wall could be molded closed to avoid the necessity of plug 44.

While the apparatus hereinbefore described is effectively adapted to fulfill the objects stated, it is to be understood that the invention is not intended to be confined to the particular preferred embodiments of rocker switch with integral off lock disclosed, inasmuch as they are susceptible of various modifications without departing from the scope of the appended claims.