Background of the Invention

This invention relates generally to a heat activated dispenser, and more particularly, to a light bulb heated dispenser.

There are a number of dispensers available for adding to the ambient any one of a number of materials. Vaporizers, for example, boil water and additives in a controlled manner to dispense water vapor and the additives into the ambient to treat various ailments. Aerosol cans provide a timed release of insecticide into the ambient. Metallic cup-like attachments are available which sit on or over a light bulb. The cup provides a reservoir for a volatile material which is boiled off and added to the ambient by the heat from the light bulb.

Although the foregoing dispensers have some utility in specific applications, they also have notable disadvantages or drawbacks. The vaporizer, for example, is bulky, has limited range, requires set-up, and must be stored between uses. The aerosol can is limited in number of materials which can be dispensed (vapor pressure, for example, must be such as to provide a gas at room temperature) , has a short effective life, and must usually be used to completion once activated. The cup-like attachment requires the addition of

liquid additives, and is potentially dangerous because the metallic cup acquires a high enough temperature to cause skin burns.

Accordingly, a need existed for an improved dispenser which would overcome the problems of the aforementioned dispensers.

It is therefore an object of this invention to provide an improved heat activated dispenser.

It is a further object of this invention to provide an improved light bulb activated dispenser.

Brief Summary of the Invention

The foregoing and other objects of the invention are achieved by a diatomite heat activated dispenser. A volume of compacted diatomite is shaped to accept heat from a heat source such as a light bulb. A vaporizable material to be dispensed is charged into the volume of diatomite, for example, by vacuum impregnation.

Brief Description of the Drawings

Figure 1 illustrates, in vertical cross section, a heat activated dispenser adapted for use with a light bulb; and

Figure 2 illustrates, in horizontal section, a preferred embodiment of heat activated dispenser in accordance with the invention.

Detailed Description of Preferred. Embodiments

This invention relates to heat activated dispensers; for purposes of illustration only, the invention will be described with reference to specific embodiments adapted to receive heat from a light bulb, but it is not intended that the invention be limited to such specific embodiments.

Figure 1 illustrates, in vertical section, a heat activated dispenser 10 in accordance with the invention. Dispenser 10 is specifically adapted for use with a standard light bulb 12 as a heat source. .The dispenser includes a volume 14 of compacted diatomite particles shaped to fit around a heat source, in this illustration the light bulb 12.

Diatomite, also known as diatomaceous earth, is a fine siliceous earth composed mainly of cell walls of diatoms. In this application the diatomite can be used either calcined or uncalcined. The diatomite has a low bulk density of only about 5-10 Ib./cu. ft. Most importantly, however, diatomite has a specific surface of about 214 sq. ft./gm. and an absorption capacity of about 3 grams/gram. These properties allow the diatomite dispenser to absorb and hold a large quantity of volatilizable material. In addition, diatomite is relatively inert, has a softening temperature over 1,400°C, and is a poor thermal conductor.

The volume of diatomite particles is preferably formed to the desired shape by high pressure compacting. Volume 14

is formed so that concave interior surface 16 is radiused to fit over a standard light bulb, such as a standard 100 watt light bulb, with minimal clearance.

The dispenser also preferably includes a vent opening 18 for the escape of gases generated by the heating of the dispenser. The dispenser also preferably includes a plurality of channels 20 which extend from the base opening 22 of the dispenser, along the interior concave walls, to the vent opening.

The positioning of the vent hole and channels is seen more clearly in Figure 2. The channels, in a preferred embodiment, are tapered from wide near the base opening to narrower near the vent opening. The tapering channels increase the velocity of heated gases flowing around the light bulb and thus impart a distinct upward flow direction to the gases through the dispenser. Four channels 20 are illustrated, but more or less can be utilized, as needed in a particular application.

The volume of diatomite preferably has the shape of a right circular cylinder. The outside 24 and base 26 of the cylinder can be coated with a high temperature paint, epoxy, or the like to inhibit sloughing of particles of diatomite. The interior 16 and top 28 are left uncoated.

The material to be dispensed by the heat activated dispenser is charged to the diatomite. The material can be charged by vacuum impregnation, soaking the diatomite in the material in liquid form, or the like, depending on the

nature and characteristics of the material. The material to be dispensed is selected from materials (preferably liquids) having a heat of vaporization such that when sufficient heat is imparted to the dispenser and thus to the material, the material is readily vaporized. Some materials will require an adjustment of the heat of vaporization, for example by mixing or compounding, to be suitable for certain uses.

Materials can be charged to the diatomite for treating medical ailments, for the dispensing of medicaments, for insect repelling or eradication, for odor masking, or the like. A quantity of heat is then applied to or conducted into the diatomite to cause a phase transformation and release of the the charged material from the volume of diatomite in the gaseous state. The gaseous material released from the diatomite on which it is adsorbed or absorbed passes through channels 20 and upward through vent opening 18. There will also be a release of the gaseous material or vapors from the other surface of the diatomite.

Because of its inert and refractory nature, the diatomite is not involved chemically with the material being dispensed, but rather acts as a binder or source for the material. Also, because of the low thermal conductivity of the diatomite, the outside of the dispenser remains relatively cool and safe to touch.

As a specific but non-limiting example, a diatomite heat activated dispenser is charged with perfume. The dispenser is placed on one or more light bulbs in lamps in a

room and the lamps are switched on. As the light bulbs heat the interior of the dispenser, perfume is emitted into the room ambient.

Thus it is apparent that there has been provided, in accordance with the invention, a heat activated dispenser that meets the objects and advantages set forth above. The invention has been described and illustrated with respect to certain embodiments thereof, but it is not intended that the invention be limited to these embodiments. Those skilled in the art will recognize, after review of the foregoing description, that variations and modifications differing from these embodiments but falling within the spirit of the invention are possible. Other heat sources and shapes of dispensers, for example, are contemplated. All such variations and modifications as fall within the appended claims are therefore considered within the scope of the invention.