US3385944A - Electric illuminating light dimmer control unit - Google Patents

Description

c. MACKIEWICZ ETAL 3,385,944

May 28, 1968 ELECTRIC ILLUMINATING LIGHT DIMMER CONTROL UNIT 2 Sheets-Sheet 1 Filed Sept. 12, 1966 INVENTOR.

31 M Qwy- Arron/vars,

M y 28, 1968 c. MACKIEWICZ ETAL 3,385,944

7 ELECTRIC ILLUMINATING LIGHT DIMMER CONTROL UNIT Filed Sept. 12, 1966 2 Sheets-Sheet 2,

45 2250 46 15 1g In? .1

ATTORNEYS.

United States Patent 3,385,944 ELECTRIC ILLUMINATING LIGHT DIMMER CQNTROL UNIT Czeslaw Mackiewicz, Trumbull, and John Pistey, Fairlield, C0nn., assignors to Harvey Hubbell, Incorporated,

Bridgeport, Comm, a corporation of Connecticut Filed Sept. 12, 1966, Ser. No. 578,536 14 Claims. (Cl. 200-167) ABSTRACT OF THE DISCLOSURE A light dimmer control unit having a wall plate and including mounted thereon a dimmer control including a dimmer wheel, a three-position switch, a switch bar, and an optional cover optionally hung on the wall plate having apertures for passage of the dimmer wheel and the switch bar. The wall plate is securable upon a wall box in heat transfer and electrical grounding relation thereto.

This invention relates to a electric illuminating light dimmer control unit, and more particularly to such an improved unit having a safely grounded improved wall plate on which all of the components are mounted for unit handling and a removable decorative cover.

Recently electric illuminating light dimmers have gained in popularity in private home use where they are used selectively to control the intensity of illumination of permanently installed incandescent light fixtures to provide atmosphere in a room. In the known dimmers, the dimming circuitry is such that a dimmer dial is usually provided that may be selectively rotated by the user over an infinite range of light intensity values from a minimum to a maximum brightness level at extremes of this dial adjustment. These light dimmers of the known prior art construction are generally permanently housed in a casing to protect the user from the internal current carrying parts. The entire casing is generally grounded through the usual wall box upon or in which it is mounted in the wall of the room with only the dimmer dial protruding from the casing where it is accessible for manual adjustment.

The prior art form of light dimmer is objectionable because hot spots are generated in the usual sealed dimmer units since the adjustable dimmer control dial must be set at a maximum position for full brightness, requiring a full current load to pass through the dimmer subcircuitry. This heat buildup may become a fire hazard if the units are not properly installed in the wall, and may at the very least be deterimental to the unit itself by shortening its useful lifetime. A further objection to these sealed light dimmer units is aesthetic considerations. Since it is not uncommon for the modern homeowner to redecorate his home periodically, he desires readily adaptable and replaceable fixtures. The known dimmer, housed in a permanently sealed casing to meet rigorous safety requirements, necessitates installation of an entire sealed unit which may be unsightly in a subsequent room decor.

Accordingly, it is the primary object of this invention to provide an improved light dimmer control unit having a fully grounded wall plate on which all components may be mounted and which is safe even when exposed, and which is provided with a unique mounting means for mounting readily replaceable decorative covers.

A further object is to provide a light dimmer control unit which avoids hot spots by providing for heat dissipation in several ways. First, circuitry is provided that enables full brightness to be achieved in an on position that bypasses the dimmer sub-circuitry altogether, thereby generating no heat at maximum load condition. Second, the decorative cover is provided at bottom and top with air vents which allow cooling air to rise through the cover in the vicinity of the elements of the dimmer subcircuitry by a chimney effect. Third, heat dissipation through direct heat conductivity is also present since all the heat generating components are mounted on the wall plate which is directly mounted to the usual wall box, all in heat conducting relationship. Fourth, a certain amount of heat is dissipated through the copper leads wired to the dimmer unit.

Another object is to provide in an improved light dimmer control unit an improved dimmer wheel which is mounted to the wall plate in a unique manner.

To accomplish these objects in one form, a light dimmer control unit is provided which comprises a metallic wall plate arranged to be attached to a conventional wall box, in gOOd heat conducting relationship, in such a manner as to fully ground the plate; a switching and dimming circuitry housing mounted to and on the rear of the wall plate which is positionable within the wall box; a threeposition switch means mounted at the front of the wall plate, and a manual dimmer adjusting means mounted at the front of the wall plate. A decorative cover may or may not be placed over the front of the wall plate at the option of the user, even after the wall plate is mounted on the wall box.

Other objects and fuller details of that which we believe to be novel and our invention will be clear from the following description and claims taken with the accompanying drawings wherein:

FIG. 1 is a perspective view of the dimmer unit constructed in accordance with the invention with the decorative cover mounted in position;

FIG. 2 is a front elevational view of the dimmer unit of FIG. 1 with the decorative cover partially cut away;

FIG. 3 is a view taken substantially along line 3-3 of FIG. 2 showing the switch and dimmer wheel;

FIG. 4 is a view taken substantially along line 4-4 of FIG. 2 showing the manner in which the dimmer wheel is mounted on the wall plate;

FIG. 5 is a view taken substantially along line 5-5 of FIG. 2 showing details of the switch operating means;

FIG. 6 is a fragmentary perspective view showing the manner in which the inner upper end of the decorative cover is mounted to the upper end of the wall plate;

FIG. 7 is a perspective view of the dimmer unit of FIG. 1 mounted on a wall box with the decorative cover removed; and

FIG. 8 is an enlarged right end elevational view showing in detail the switch operating means.

With particular reference to FIGS. 1, 3 and 7, there is illustrated one embodiment of the light dimmer control unit according to the present invention. The unit is generally designated by the reference numeral 10 and comprises .a metallic wall plate 11 upon the front face of which is mounted a switch bar 12 and a dimmer adjusting wheel 14. These are selectively manually operative means for controlling the circuitry elements within the circuitry housing box 16 which is rigidly removably secured to the rear face of wall plate 11. The wall plate may be mounted directly to the wall box 18, which may be of conventional form and is disposed in the wall W. The unit is safe to use as thus described without an additional cover, since it is fully grounded and fully closes the wall box, and has been approved by Underwriters Laboratories. A decorative cover 20 having appropriately configured apertures for the switch bar 12 and dimmer wheel 14 optionally may be removably mounted upon the wall plate 11. If employed, the cover 20 may be made of a suitable plastic material, and as it is removable it may be supplied in a variety of decorator colors.

The dimmer control unit of the present invention will now be described in detail with reference to FIGS. 2 through 8. As already referred to, the wall .plate 11 with the circuitry housing 16 attached to it at the rear thereof is mounted On the usual wall box 18, as by the usual mounting screws 22 and 24 that pass through the wall plate and are threadedly anchored in lugs 0n the wall box. The mounting of the screw 22 will be described in detail subsequently. The screw 24 passes through a slot 25 in the plate 11, which slot permits some adjustability in mounting. A dimmer potentiometer 28 positioned within the circuitry housing box 16 has a shaft 30 extending through the wall plate to the face thereof, upon which is mounted selectively rotatable control gear 56. A threeposition switch 31 also housed in the circuitry housing box 16 has a .portion that extends through the plate 11 and is secured to the plate 11 by a nut 32. An electronic package 33 comprising the dimming sub-circuitry, which may be of the type covered in copending application of Misencik and Lee for patent for Phase Controlled Alternating Current Circuit, filed Aug. 8, 1966, Ser. No. 570,798, assigned to the assignee of the instant application, is mounted on the rear of wall plate 11 and electrically wired to the potentiometer 23 and switch 31.

The wall plate 11 has a raised circular boss 34 concentric with an aperture 35 through which the mounting screw 22 extends, and against which the end of the hub of dimmer wheel 14 bears. The dimmer wheel comprises a substantially cylindrical hub-like central body 36 from which radially extends a disk comprising a circular front face wall 37 having at its periphery a knurled bevel edge 38. The dimmer wheel 14 is secured to the front face of the wall plate 11 by a bushing 4h upon which the dimmer wheel is rotatably mounted. The bushing has a cylindrical body portion 44 having a flange at one drical body 44 is received in a central aperture 42 in the dimmer wheel body 36, and the flange 45 bears on shoulder 43 disposed on the body 44 concentrically to the central aperture 42. The boss 46 extends through the wall plate 11 and is spun over at 48 thereby permanently securing the bushing and dimmer wheel to the wall plate. The spun over portion 48 is seated in the recess provided therefor at the rear of the raised circular boss 34 thereby allowing the wall plate 11 to be mounted flush on the wall box 18. The bushing 41 is provided with a central passage 50 for receiving the shank of the wall plate securing screw 22, and is further provided with an enlarged portion 52 to house the head of the securing screw 22. The dimmer wheel has a gear toothed portion 54 disposed on the cylindrical central body 36 which coacts with gear 56 secured upon the potentiometer shaft 30. Thus, it can be readily seen that the dimmer sub-circuitry is controlled by the selectively manually rotatable dimmer wheel 14 through the intermediate control gear 56. Both wheel 14 and control gear are preferably made of electrical insulating material, such as any suitable available plastic material.

The wall plate 11 is provided with suitable means to mount the switch bar 12 comprising upstanding lugs 60 formed integral with and disposed on either side of the wall plate, and the lugs have pins 62 struck therefrom. The switch bar 12 is preferably made of a plastic material and has pivoting arms 64 extending therefrom defining keyhole mounting slots at their ends. Each keyhole slot comprises: a substantially circular opening 66 provided as a bearing seat for pins 62; and leg members 68 having camming faces 69, the innermost edges of which define an opening smaller than the diameter of the openings 66 and pins 62. Therefore, the camming faces 69 serve to direct the pins 62 into their seat openings 66 while causing the leg members 63 to be deflected outwardly and to snap about the pins s2 once in place thereby insuring a secure fit. The switch bar 12 further comprises a partial cylindrical surface wall portion '71), from which the handle 71 of the switch bar extends, and a slot 72 accessible from the rear of the switch bar and defined by the walls of the bar handle and arranged to receive the actuating pin extension '74 of the three-position switch 31.

The unit 10 as just described is fully operative and safe to use. At the option of the user one of a number of interchangeable decorative covers may be hung on the above wall plate as will become apparent when mounted in a conventional wall box, as illustrated in FIG. 7. The switch bar may be selectively adjusted to its OFF, ON (full brightness), or DIM position, and the wheel 14 may be adjusted to the desired intensity level if the unit is set for DIM. The electronic subcircuitry package 33 and wiring are such that when the unit is set for ON the potentiometer and dimming subcircuitry are bypassed, and full line current passes directly through the incandescent light, thereby eliminating heat generation in the dimming sub-circuitry.

The decorative cover 20 which is preferably molded of a suitable plastic material in a variety of colors comprises: a deeper lower section 86, behind which is housed the switching and dimming mechanism; a shoulder 88; and a shallow section 90, which houses merely the cover hanging means. In the front wall of section 86 of the cover 21} is a rectangularly slotted aperture 92 through which the handle 71 of the switch bar 12 extends so that the user may selectively manually actuate the switch 31. Another aperture 94 is provided which extends through the shoulder 88 and the face of the shallow section of the decorative cover, and allows a portion of the dimmer wheel 14 to extend through the decorative cover 20 so that it is accessible to be selectively manually rotated to the desired dimming setting.

The means by which the decorative cover is hung on the wall plate 11 can best be seen in FIG. 6. The wall plate 11, at its front, includes upstanding lugs 76 lanced out of the plate and having fingers 78 thereon extending upwardly and arranged to support a cover hanger wire 96 that is secured at the rear of the cover. The wall plate 11 is further provided with a lug $6 lanced out of the bottom of the Wall plate and having a threaded hole 82 therethrough arranged to receive a cover retaining screw 84. The wire 96 is trained over pins 98 which are molded on either side of the rear face of the decorative cover at the top thereof, and this wire is held in place by locking washers 100 which are firmly secured on the pins 98. A slot 102 is provided in the bottom wall 101 of the cover 20 which receives the shank of the cover retaining screw 84, but is too narrow to allow the head of screw 84 to enter, thereby firmly securing the decorative cover 20 upon the Wall plate 11 when the screw 84 is further threadedly engaged in hole 82. The decorative cover is also provided with slots 194 in its bottom wall 101 which allow air to move upwardly between the cover and wall plate, and out aperture 94, in order to cool the unit, by a chimney effect.

When mounting the decorative cover 20 on the wall plate, after the latter is secured on the wall box, the

cover hanger wire 96 is hung on the lugs 76 and adjusted so the switch bar 12 and dimmer wheel 14 extend through the apertures 92 and 94, respectively, provided therefor in the decorative cover. To firmly secure the cover in place it is pivoted on the wie-lugs axis until the slot 102 passes over the shank of the retaining screw 84, and then the screw 84 is tightened, by means of a screw driver or other suitable tool, until its head tightly engages the bottom cover wall 101.

The partial cylindrical portion 70 of the switch bar serves as a bearing surface at its ends, which are received in molded concave seats 108 provided for it on the rear side of the cover at either side of the aperture 92. The cover is further provided with bevelled faces 106 defined by the upper and lower Walls of the aperture 92 so as to eliminate interference between the upper and lower exterior edges of the aperture 92 when the switch bar handle is in its upper or lower position (see FIG. 8).

In order to operate the dimmer control unit of the present invention, the user need merely manually selectively move the switch bar handle 71 from the OFF position to the DIM position. When the bar is in the DIM position the user may manually selectively rotate the dimmer Wheel to the desired intensity of the incandescent light fixtures. The user may achieve maximum brightness of the incandescent fixtures by switching the bar to the ON position thereby bypassing the dimmer sub-circuitry. This feature, as mentioned before, eliminates heating up of the unit during maximum load conditions. With reference to FIG. 3, the switch bar handle 71 is shown in a solid line central position, and dotted line upper and lower positions; in practice, the central position is OFF, the upper DIM, and the lower ON.

As will be noted in FIGS. 1, 2 and 3, the schematic arrows show the chimney effect of the air flow through the decorative cover as provided in the cover design to eliminate overheating of the unit. Air enters the slots 104 in the bottom wall 101 of the cover 20, and rises through the cover, between the wall plate .11 and the cover. As it rises it is heated in the vicinity of the circuit housing box 16 from where it rises further and passes out of the cover box through the dimmer Wheel aperture 92. It should be noted that it is not necessary to employ the decorative cover, since the dimmer control unit may be used as shown in FIG. 7. If this type of mounting is employed, it eliminates the necessity for cooling the unit with a constrained air flow since ambient air currents in the room in which the unit is mounted will cause the localized heating of the air about the unit to be dissipated.

It is understood that the present disclosure has been made only by way of example and that numerous changes in details of construction and the combination and arrangement of parts may be resorted to without departing from the true spirit and the scope of the invention as hereinafter claimed.

, What we claim as new and desire to secure by Letters Patent of the United States is:

1. A light dimmer control unit comprising a fiat metallic wall box covering wall plate having a front face and a rear face; light switch means carried by said plate in heat transfer and electric insulating relation thereto; dimmer control means separate from said light switch means carried by said plate in heat transfer and electric insulating relation thereto; and means for mounting said plate on a wall box with the rear face of said plate being contiguous with the wall box in such a manner as to fully ground said plate and with said switch means and said dimmer control means disposed in said wall box.

2. The light dimmer control unit defined in claim 1 wherein said light switch means comprises a three-position switch having an off position, a dim position which activates dimmer control sub-circuitry, and a maximum brightness on position which bypasses said dimmer control sub-circuitry.

3. The light dimmer control unit defined in claim 2 wherein said three-position switch is: mounted on the rear of said plate; provided with a selectively operable switch lever which extends through said wall plate to the front face thereof, and includes a switch bar pivotally mounted on said wall plate at the front face thereof and arranged to receive said switch lever to selectively move said lever to any one of the three switch positions.

4. The light dimmer control unit defined in claim 3 wherein said switch bar comprises a longitudinal bar defining an internal longitudinal slot arranged to receive said switch lever; said bar having a plurality of depending pivot arms, each of said arms defining seats arranged to receive a pivot pin carried by said wall plate.

5. The light dimmer control unit defined in claim 1 wherein said dimmer control means is actuated by a dimmer wheel rotatably mounted on the front face of said wall plate.

'6. The light dimmer control unit defined in claim 5 wherein the dimmer wheel mounting means comprises a bushing seated in a central aperture in said wheel; said bushing having a portion thereof extending through said wall plate to the rear face thereof and formed to retain said dimmer wheel on said wall plate.

7. The light dimmer control unit defined in claim 6 wherein said dimmer control means comprises a rotatable shaft extending through an aperture in said wall plate; a gear disposed on the front face of said wall plate mounted on said shaft; and a mating gear upon said dimmer wheel co-axial with said bushing.

8. The light dimmer control unit of claim 6 wherein said plate mounting means includes a securing screw that extends through said bushing and is arranged to be anchored in the wall box.

9. The light dimmer control unit defined in claim 1 wherein: said light switch means comprises a three-position switch mounted on the rear face of said wall plate including a selectively operable switch lever which extends through said wall plate to the front face thereof, a switch bar pivotally mounted on the front face of said wall plate having a longitudinal slot arranged to receive said switch lever, and a plurality of depending pivot arms each of which defines a seat arranged to receive a pivot pin carried by said wall plate; said dimmer control means comprises a rotatable shaft extending through the wall plate, a gear disposed on the front face of said wall plate and mounted on said shaft, :1 dimmer wheel rota-tably mounted on the front face of said wall plate and dimmer wheel mounting means comprising a bushing seated in a central aperture in said wheel, said bushing having a portion extending through said wall plate to the rear face thereof which is formed to retain said wheel on said wall plate; and a mating gear upon said wheel coaxial wit-h said bushing.

10. The light dimmer control unit defined in claim 9 including a decorative cover having a face which defines an aperture to receive said switch bar of said light switch means and an aperture to receive said dimmer wheel of said dimmer control means; said cover being arranged to be mounted upon said wall plate and having mounting means including a wire-like member disposed on the interior at the top thereof; and wherein said wall plate comprises a plurality of fingers disposed upon its front face and arranged to receive said wire-like member in such a manner as will allow said cover to hang on said wall plate.

11. The light dimmer control unit defined in claim 1 wherein a decorative cover is arranged to be removably mounted upon said wall plate; said cover face defining an aperture to receive a switch bar of said light switch means and an aperture to receive a dimmer wheel of said dimmer control means.

12. The light dimmer control unit defined in claim 11 wherein the cover has mounting means including a wirelike member disposed on the interior at the top of said cover; and a plurality of fingers disposed upon the front fiace of said Wall plate and arranged to receive said Wirelike member in such a manner as will allow said cover to hang on said Wall plate.

13. The light dimmer control unit defined in claim 11 wherein the bottom wall of said cover defines a plurality of slots provided therein to allow air currents to pass upwardly through said cover and out said dimmer wheel aperture to aid in dissipating the heat generated by the dimmer sub-circuitry.

14. The light dimmer control unit defined in claim 12 wherein said mounting means further comprises a slot in the bottom Wall of said cover and a securing screw extending therethrough and anchored in said plate.

References Cited UNITED STATES PATENTS Re. 26,119 12/1966 Slater 307-l46 3,201,597 8/1965 Balan 30788.5 3,058,020 10/1962 Balan 17466 10 ROBERT K. SOHAEFER, Primary Examiner.

H. O. JONES, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,385,944 May 28, 1968 Czeslaw Mackiewicz et al.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 23, "a" should read an line 37, "this" should read the Column 3 line 52 after "one" insert end and a reduced boss 46 at the other end. Thegylinline 54, "46" should read 45 Column 5, line 5, "wi'e-lugs" should read wire-lugs Signed and sealed this 7th day of October 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr. WILLIAM E. SCHUYLER, J

Attesting Officer Commissioner of Patents

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