Christmas Tree Lighting Control

This invention relates generally to Christmas tree lighting and more particularly to a Christmas tree lighting control that when in operation, effects a continually changing light intensity output throughout all the lights of a tree and in a predetermined manner to produce a twinkling or shimmering of the lights rather than the conventional method of making and breaking the circuit through the lamps to produce a flashing or by so reducing the voltage thereto as to produce a similar flashing result.

With the increasing desire of the public for movement or action in Christmas tree lighting, the use of string flashers or individual flasher bulbs has become widely accepted. While such devices do relieve the lifelessness of a lighted tree, the violent action of flashing lights can become quite annoying particularly when such flashing affects the entire string. This is generally the case even when not looking directly at the tree. The on and off of any light source within a room, such as the flashing of tree lights, can become quite distracting. This is particularly true when the flashing of two or more strings reach a condition of synchronization so as to flash simultaneously. Such a condition will invariably occur when any flasher apparatus operates individually whether in bulbs or strings.

It is an object of the present invention to provide a new and improved Christmas tree lighting control which, when in operation, applies a plurality of continually changing power conditions to all the lights of a tree and in a predetermined order.

A further object is to provide a voltage control for Christmas tree lighting wherein the circuits to the lights are never interrupted to cause flashing, but is applied as a continually changing power factor to produce slight changes in light intensity and in such a manner as to effect a twinkling or shimmering of the lights of the entire tree.

A still further object is to provide a Christmas tree lighting control that will apply varying power conditions to a plurality of Christmas tree lighting strings simultaneously and in a manner to produce a coordination of lighting effects between the individual strings without materially varying the overall light intensity of the system.

A further object is to provide a control for Christmas tree lights preferably of the miniature series wired type and, if desired, may be used in combination with individually flashing bulbs.

In order that this invention may be more readily understood, reference is now made to the accompanying drawings wherein:

FIG. 1 is a side view in elevation of the assembled device of the invention as inclosed within the control housing.

FIG. 2 is an electrical schematic of the device of the invention and as one of four such units contained within the housing shown in FIG. 1.

FIG. 3 is a view in elevation of the motor drive as it relates to the control operating cam portion of the device.

Referring now to the drawings, and more particularly to FIG. 1 thereof, wherein is shown the assembled device of the present invention and as will be generally designated 5 and to which may be connected strings of Christmas tree lights with the lights being of the series wired miniature type. The assembly 5 includes a mounting base 6 to which the perforated cover 7 is attached and wherein is enclosed the working mechanisms of the device. The connector 8 and power supply cord provides means for electrically connecting the device to a conventional 110 volt AC power supply source.

Extending from the end of the cover in the manner shown, is a number of electrical outlets 9 and into which, when in use, strings of Christmas tree lights are plugged. The lead wires 10 to the various outlets may be of any length desired, preferably, sufficiently long as to extend well into the tree for easy access to the lighting strings while allowing the control to rest beneath the tree or possibly some distance away.

FIG. 2 shows the arrangement of the control units of the device that are mounted within the case 7 and their relationship electrically to the Christmas tree lighting string 11 to which it is connected by the outlet 9. The device includes a resistor element 13 which is preferably formed as a winding about a bemetallic strip 14 secured by branket 15 to the insulating base 6 of the device. Insulation 16 electrically isolates the resistors from the strip 14 except at point 17 whereupon the bare wire of the resistor is wound about the strip to make electrical connection therewith at the position shown.

Formed upon the free and of the strip 14 is a bent-down tang like member 18 so located as to extend over and maintain in a depressed position a spring contact finger 19 secured to the base 6 as by brackets 20 and 15. A plastic reset button 21 extends through the cover depression 22, FIG. 1, and against the contact finger 19 to depress the finger for electrical reset if released from the tang 18 by thermal movement of the strip 14, as will hereafter be more fully described.

Electrically connected by leads 23 and 24 across the resistor 13 are flexible contact members 27 and 28 which form part of the circuit controlling elements of the unit. The third flexible contact member 29 is electrically connected through a half wave rectifier or diode 26 to the contact member 28 by way of lead 30 in the manner shown.

In operation of the device thus far described, current is suppoied by was of the power source 31 to connector 8 thusly to put in operation a back-geared motor drive 35 having a shaft speed, desirably, of 20 revolutions per minute. The motor drives the cam 36 of the control by way of shaft 37. From the connector 8 circuit is likewise completed to the lamp string 11 by way of the outlet 9 after having passed through the bracket 20, the contact finger 19, the resistor 13 and diode 25. With both the resistor and diode 26 now in the lighting circuit, the lamps of the string are now at their lowest stage of brightness.

Spring contact member 27 which, by reason of the shown position of cam 36, is now in open circuit with respect to the spring contact member 28. As the cam is rotated, contact member 27 is forced by cam motion into electrical engagement with the contact member 28 to effect a shorting out of resistor 13 to cause a noticeable increase in brightness in the lamps by now applying therto a higher voltage relative to the voltage reducing value of resistor 13. Further rotation of the cam drives all of the contact members 27, 28, and 29 electrically together to short out both resistor and diode 25 to effect full brightness in the lamps by applying line voltage thereto by way of the bimetallic strip 14 and contact finger 19. Further rotation of the cam starts movement of the contact apart and with the separation of the three contact members 29, 28, and 27 the resistor and diode are again connected in the lighting circuit to complete one operation cycle of the device.

The configuration of the cam, as shown by the example 38, may be selectively varied between the four units of the control to produce a more random lighting effect throughout the lights of a tree. The operating interval between such light intensity changes should preferably be between 1 to 2 seconds, however, this may be varied selectively depending upon the design of the cam relative to the motor speed. The contacts member 27, 28, and 29 may be closed and opened in any sequence required to produce the desired effect. The cams of the four control units of the device are positioned with respect to each other preferably to prevent any light intensity changes between independently connected strings occuring simultaniously. This difference in the cams and their settings along with possible small variations in the resistors of the controls units will produce an overall shimmering and twinkling of the lights of a tree that is very pleasing and restful to observe and totally unobtainable by any form of independently operating device, such as, for example, a conventional flasher mechanism.

The device of the present invention is primarily designed for use with low current Christmas tree lights of the series wired miniature type and with resistor elements 12 being such as to produce the necessary voltage drop without overheating providing that only one or possibly two such miniature lighting strings are plugged into a single outlet of the device. However, if the electrical load upon the resistors is too great, as by plugging into one of the outlets of the device a greater number of strings then intended or attempting to connect therewith a large string of parallel wired lamps, the resistor elements will overheat to cause deflection of the bimetallic strip 14 from its contact with the finger 19 to free the latter allowing it to snap to its open circuit position with respect to the strip 14. Holding down the reset button 21 will not damage the mechanism which cannot be reset for operation until the overload upon the line has been eleviated.

While the design of the device, as herein shown, places the diode or half cycle device between the shorting contacts 28 and 29, it is understood that the positions of the diode and resistor 13 may be reversed with respect to these shorting contact members. It is further desired that during the operation of the device that the power factor to a lighting string connected with the device not be reduced to a valve that would cause the lamp luminous to deminish to what would appear to an observer as a flashing of the lamps.

While one version of the device is herein shown and described, it is understood that numerous variations and modifications may be resorted to without departing from the spirit and scope of the invention disclosed.