US3492460A

US3492460A - Heater for aerosol foam dispensing containers

Info

Publication number: US3492460A
Application number: US703933A
Authority: US
Inventors: Irving Reich
Original assignee: Carter Wallace Inc
Current assignee: Meda Pharmaceuticals Inc
Priority date: 1968-02-08
Filing date: 1968-02-08
Publication date: 1970-01-27
Anticipated expiration: 1987-01-27

Description

I. REICH Jgn. 27, 1970 HEATER FOR AEROSOL FOAM DISPENSING CONTAINERS Filed Feb. 8, 1968 FIG. 2

INVENTOR IRVING REICH ATTORNEY-3 United States Patent U.S. Cl. 219-291 3 Claims ABSTRACT OF THE DISCLOSURE An electrical heating device is provided for heating foam products as they are discharged from aerosol containers. The device instantaneously heats foam products,

such as foam shaving lather, by flowing the foam be tween and in direct contact with a pair of spaced electrical conductors carrying an electrical potential. The foam completes the electrical circuit between the conductors, and the resistance of the foam to the flow of electrical energy generates heat and raises the temperature of the foam substantially above room temperature.

This invention relates to a heating device for aerosol containers, and more particularly to an electric heater for directly and instantaneously heating foam products, such as foam shaving lather and the like, as they are discharged from the container.

Conventional aerosol containers use a propellant gas to discharge foam products from their containers. Generally, the propellant gas is dispersed throughout the product under pressure and in liquefied form. Upon release of the discharge outlet of the container, the propellant gas forces the product out of the container and, simultaneously, expands to form gas bubbles and generate the foam.

Expansion of the propellant from a liquid to a gas, however, has a cooling effect on the foam product. This cooling effect is particularly undesirable in shaving lathers, because cold shaving lather foams are not only uncomfortable but also slow in softening the beard for the shaving operation. Human hair is more easily shaved, however, when softened by the penetration of moisture from the lather, and this softening effect increases with increasing lather temperature.

For this reason numerous heating devices have been proposed for heating foam shaving lathers as they are discharged from their containers to increase the ease and effectiveness of shaving.

Foam shaving lather is difficult to heat, however, since the gas bubbles in the lather act as heat insulators. Further, the foams have a high viscosity and although it is desirable to constrict the passage of foam so that heat can be rapidly transferred to it, such constricted fiow prevents the heated foam from being supplied to the user at a useful rate.

Some of the previously proposed devices for heating foam shaving lather use electrical heating elements to heat a conduit or tube through which the foam passes. Generally, the heating element comprises an electrical resistance wire that surrounds the outside of the tube and indirectly heats the lather as it passes through the tube. Other devices provide a reservoir for hot tap water that jackets the tub and also indirectly transfers heat to the lather as it passes through the tube.

These devices, however, have generally not proven entirely satisfactory in heating foam shaving lather to the desired temperature in a convenient length of time. Desired foam temperatures have not been obtainable in such devices unless the flow rate of the foam is reduced substantially so that the residence time in the device is long enough to allow sufficient transfer of heat to the foam. At this reduced flow rate, however, a considerable amount of time is necessary to accumulate sufiicient amounts of lather for shaving and his accumulation process also allows the foam to cool.

These prior-art, indirect heat transfer devices also require a considerable preheating time between the time the heating element is actuated or the reservoir is filled with hot water and the time the device becomes hot enough to heat the foam.

For these reasons, it is desirable to provide an improved heater for an aerosol container that requires little preheating time; that instantaneously heats the foam product as it is discharged form the container; and that delivers the required amount of hot shaving lather to the user at a desirable flow rate.

Accordingly, it is a primary object of this invention to provide a new and improved electrical heating device for rapidly heating foam products as they are discharged from aerosol containers.

Another object of this invention is to provide an electrical heating device that directly and instantaneously heats foam shaving lather as it is discharged from an aerosol container to a temperature substantially above room temperature, and that supplies heated foam lather at a desirable flow rate.

Still another object of this invention is to provide an electrical heating device for instantaneously heating foam shaving lather that utilizes the electrical resistance of the foam itself to generate the energy required to heat the foam.

A further object of this invention is to provide an improved electrical heating device for instantaneously heating foam shaving lather that can be removably afiixed to the outlet of an aerosol container.

A still further object of this invention is to provide an improved electrical heating device for heating foam shaving lather that is adaptable to all sizes of aerosol containers, that is inexpensive to manufacture, that is rugged and compact, and that is convenient, reliable, and safe in operation.

Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned by practice of the invention, the objects and advantages being realized and attained by means of the instrumentalities, devices, and combinations particularly pointed out in the appended claims.

To achieve the foregoing objects and in accordance with its purpose, this invention, as embodied and broadly described, comprises an electrical heating device for heating foam as it is discharged from the outlet of a valve-actuated aerosol container. The heating device includes: a housing having a chamber for conducting foam through the housing; housing inlet means communicating with the outlet of the container for conducting foam discharged from the container into the chamber; housing outlet means for discharging heated foam from the chamber; and spaced electrical conductor means located within the chamber and exposed to the flow of foam through the chamber, said conductor means being connectible to a supply of electrical energy. The flow of foam through the chamber completes the electrical circuit between the conductor means, and the electrical resistance of the foam to the flow of electrical energy produces heat which raises the temperature of the foam as it passes through the chamber.

The accompanying drawings which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention, and, together with the description, serve to explain the principles of this invention.

Of the drawings:

FIG. 1 is a perspective view showing the heating device of this invention aflixed to the outlet of an aerosol container; and

FIG. 2 is an enlarged fragmentary sectional view of the heating device of FIG. 1.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory, but are not restrictive of the invention.

Reference will now be made in detail to the present preferred embodiment of this invention, an example of which is illustrated in the accompanying drawings.

The present invention provides an electrical heating device for aerosol containers that instantaneously heats foam shaving lather as the lather is discharged from the container.

A typical aerosol container is shown in FIG. 1. Container 10 is provided with a valve actuator 12 and a discharge spout 14. As is customary, the shaving lather product is maintained in container 10 under the pressure of a propellant gas, allowing for discharge of the product from the container.

Referring to FIGS. 1 and 2, the heating device of this invention, generally designated 16, includes an elongated housing 18 having a chamber 20 for conducting foam through the housing from an inlet end 22 to an outlet end 24, where heated foam lather is discharged from the device. Inlet end 22 is preferably connected with a slip fit to spout 14 of aerosol container 10 through flexible connector 25 but may be provided with threads or grooves for application to complementary formed portions on container spout 14. Housing 18 can be constructed of plastic or the like, and preferably has good electrical and thermal insulation properties.

As shown in FIG. 1, chamber 20 preferably has a width and length substantially greater than its thickness and confines the flow of foam through housing 18 to a thin, wide sheet. I

In accordance with the invention, spaced electrical conductor means are located within chamber 20 to heat the foam as it passes through the chamber. As embodied, and as shown in FIG. 2, the conductor means comprises a pair of spaced and substantially parallel metal plates 26 mounted to opposite inner walls 27 of housing 18.

Metal plates 26 are of electrically-conductive material, such as copper, aluminum, or the like, and are electrically insulated from each other by nonconductive housing 18. Plates 26 are directly exposed to the flow of foam through chamber 20 and are electrically connected to opposite terminals of a conventional (110 volt AC) household circuit through electrical cord 28.

In operation of the heating device of this invention, the user plugs cord 28 into an electrical outlet which supplies electrical energy to metal plates 26. Since plates'26 are electrically insulated from each other, the electrical circuit is not complete and current does not flow through the device. Valve 12 of aerosol container 10 is then actuated to discharge foam shaving lather from spout 14 through connector 25 and into inlet 22 of chamber 20. The foam passing through chamber 20 is in intimate contact with plates 26 completing the electrical circuit between them and permitting current to flow through the heating device and the foam.

Shaving lather foams and other similar foam products are not ideal conductors of electricity, and, therefore, offer substantial electrical resistance to the flow of current. Since the amount of heat generated by a given current flow is directly proportional to the resistance of the material through which the current flows, the resistance of the foam to the electrical current generates sufiicient amounts of heat to raise the foam to the desired temperature.

Metal plates 26 are preferably spaced about .06 inch apart to achieve maximum current flow and greater heating of the foam. This spacing does not constrict the chamber severely, and allows a useful flow rate of heated foam to be achieved.

Since the heat is generated in the foam lather itself, the heating device of this invention operates instantaneously, and, therefore, eliminates any time delay that was previously required to preheat indirect heat transfer devices.

Further, since electrical current can flow between plates 26 only when lather is present in chamber 20, no electrical switch or other control means to control the flow of current to the device is required. As soon as the flow of lather through chamber 20 is stopped, the residual lather in the chamber breaks down and the current flow between the plates is interrupted.

For safety reasons, however, an electric-a1 switch may be provided to control the flow of current to the heating device of this invention. As shown in FIG. 1, for example, a manually operated line switch 30 can be mounted to electrical cord 28.

The present invention thus provides a heating device for instantaneously heating foam shaving lather as it is discharged from an aerosol container. This device uses the electrical resistance of the foam itself to generate the necessary heat to raise the temperature of the foam. By increasing the temperature of the lather and thereby increasing its solubility in water, better contact with the beard and increased comfort for the shaver is afforded.

While a separate heating device for removable attachment to an aerosol container has been illustrated in the accompanying drawings, it will be understood from the above description that the heating device of this invention may also be made a permanent or integral part of the container. Further, it will be appreciated that the heating device can be cylindrical or of any other desired shape, rather than the rectangular configuration shown in the drawings.

The invention in its broader aspects is not limited to the specific details shown and described, and departures may be made from such details within the scope of the accompanying claims without departing from the principles of the invention and without sacrificing its chief advantages.

What is claimed is:

1. An electrical heating device for heating foam as it is discharged from the outlet of a valve actuated aerosol container comprising:

(a) a housing constructed from an electrically nonconductive thermally insulative material, said housing defining a chamber having a substantially rectangular cross section and coupled to the exterior of said housing through a first and a second oppositely positioned ports said ports having circular cross sections wherein the centers of said circular cross sections pass through the center of a plane which is parallel to and equally distant between opposite sides of said rectangular cross section of said chamber and contained within said rectangular cross section;

(b) a flexible housing inlet means for conducting foam discharged from said container into said chamber wherein said means is affixed to said housing about said first port opening in said housing, said flexible housing inlet means having a cross-sectional area greater than that of said first port opening;

(c) a housing outlet means affixed within said second port opening for discharging heated foam from said chamber;

(d) electrical conductor means coupled to a supply of electrical energy and afiixed to said housing on opposite faces of said chamber so as to define a pathway through said housing for the flow of foam wherein the cross section of said pathway is rectangular having the longer side of the cross section of said pathway equal to the corresponding dimen- 5 6 sion on the cross section of said chamber and the 1,265,554 5/1918 Valdes 219-292 shorter side of the cross section of said pathway 1,480,515 1/1924 DeMarchis 219 291 e ual to the diameter of said first ort. 2. The electrical heating device as described in claim 1957070 5/1934 Ludwlg 219 293 1 wherein the pathway defined by said electrical conduc- 2,188,625 1/1940 Dufour et 219 .291 tor means confine the foam within said pathway to a thin 5 ,7 5/ 9 8 Bashu 219284 X wide sheet having a thickness of about .06 inch. 2,373,351 2 1959 Lannert 2 3. The electrical heating device as described in claim 3,069,528 12/1962 Gardner 2 further comprising an electrical switch to control the flow of electrical energy to the electrical conductor means, 10 3341080 9/1967 Wittke -7 References Cited ANTHONY BARTIS, Primary Examiner UNITED STATES PATENTS US. Cl. X.R. 731,339 6/1903 Chapman 219291 2 9 214 293 299; 222 14 1,249,285 12/1917 Shoenberg 219-291 15