US3437791A - Electrical heating attachment for aerosol cans - Google Patents

Description

' April s, 1969 l c. s. GARDNER 3,437,791

ELECTRICAL HEATING ATTACHMENT EoEAERosoL cANs vFiled Oct. 21, 1965E 95 INVENTOR United States Patent O U.S. Cl. 219-301 3 Claims ABSTRACT OF THE DISCLOSURE A heating attachment detachable securement to the val-ve stem of an aerosol can has a sealed chamber with a discharge passage extending therethrough. The passage is in comm-unication with the valve stem and receives products discharged from the can. A thermostatically controlled electric heating coil is provided about the passage to heat the discharged products. A gravity operated switch in the housing permits energization of the heating coil only when the can is tilted. Short circuit protection is provided by fuses located in the plug portion of the attachment power cord. An adapter permits use of the attachment with cans having horizontally oriented discharge valves.

This invention relates to heating means and more particularly to an electrical heating unit particularly adapted to be lutilized in combination with aerosol cans. The invention is an improvement of U.S. Patent 3,069,528, issued Dec. 18, 1962, to Charles S. Gardner.

The heating unit disclosed in the above identified patent performs admirably to provide heated shaving cream foam at an optimal temperature for the most comfort in shaving. When used, and stored properly, there is little danger that it will overheat. Inasmuch as there is the possibility that it will not be, however, it would be particularly desirable to have incorporated therein a control device to prevent it from overheating. Also, there is a possibility that the heating unit may -be dropped and damaged to the extent that a leak may develop through cracks or breaks in the outer casing, or through separations in joints of abutting portions of the composite casing, or through the aperture admitting the electrical wires, or through the nozzle itself. Such leakage could allow conductive liquid (water or other similar liquid) to produce a short circuit which may be hazardous to the user. In this respect, it would also be desirable to incorporate in the heating unit a safety device to eliminate this hazard. The heating unit of the above identified patent is adapted to fit only one type of aerosol nozzle. At the present time there are many nozzles, for example, side oriented nozzles to which the heating unit of said patent cannot be adapted. Accordingly, it is an object of this invention to provide an improved heating unit and particularly a heating unit which is adapted for use with aerosol cans to heat the contents of the can as the contents is discharged.

It is another object to provide fan improved heating unit of the type described having a safety control device to preclude its overheating.

It is a further object to provide an improved heating unit of the type described having a safety control device for eliminating electrical hazard to the user.

Still another object is to provide an improved heating unit which is adapted for use with various types of aerosol nozzles.

Other objects and advantages to be derived from the present invention will be obvious in the following description and enumeration of the accompanying drawing in which:

FIG. l is a sectional view of a heating unit exemplary of the invention, including the male electrical plug, and including the valve stem portion of :a typical vertically oriented aerosol valve;

FIG. 2 is an elevational front view showing the heating unit of FIGURE 1 mounted on atypical aerosol can having a vertically oriented aerosol nozzle;

FIG. 3 is an elevational front view showing the heating unit of FIGURE l mounted on fan aerosol can having a horizontally oriented aerosol nozzle;

FIG. 4 is a top plan view of an adapter for tting the heating unit of FIGURE 1 to a horizontally oriented aerosol nozzle;

FIG. 5 is a sectional view taken substantially alonglines 5 5 of FIGURE 4; and

FIG. 6 is a sectional view taken substantially along lines 6-6 of FIGURE 5.

Similar reference characters refer to similar parts of the original invention and throughout the several views of the drawing.

Referring now to the drawing, and particularly to FIG- URE 1 thereof, thenumeral 20 represents a heating unit which can be affixed to thevalve stem 12 of an aerosol valve (not shown) for heating efliuent foam, such as shaving cream foam, as it is discharged from an aerosol can 10 (FIG. 2). The valve stem is urged into its normally closed position by a spring (not shown) within the aerosol valve which fabutsliange 16. In the conventional usage of the aerosol can 10, thecan 10 is'inverted and finger pressure is applied on thevalve stem 12, to operate the normally closed aerosol valve. The pressure within thecan 10 will then force the contents thereof outwardly through acavity 77 in thevalve stem 12. Upon the release of finger pressure, the spring will carry thevalve stem 12 back to its normal position to thereby close the valve.Threads 18 may be provided on the exterior surface of Valvestem 12 for threadably receiving a cap thereon, however, in most cases the cap is press-fitted onto the valve stem, or to the aerosol can.

Theheating unit 20 further includes a frustro-conical shell 22 which is preferably of an insulative generally rigid material such as plastic. Abase 24 having a tubular boss 26 integrally formed therewith is aixed within theybase 24, extending with the boss 26 upwardly toward the apex of the frustro-conical shell 22. A counterbored passage is provided through the tubular boss 26 and includes a wideupper portion 28 and alower portion 29 which may haveinternal threads 30 formed therein for receiving a valvestem having threads 18. Ashoulder 32 separates the twoportions 28 and 29 of the counterbore passage.

An insulative washer 34 is fixed in theupper portion 28 of the boss passage and is seated onshoulder 32. The insulative washer 34 is preferably inserted into the mold in which thebase 24 is `cast and is integrally cast therewith so that a longlasting effective moisture seal is provided. Thebase 24 is also preferably cast about a pair ofelectrical wires 48 and 50, as at S6, thereby sealing another aperture in the overall casing against moisture. With this construction, the possibility of creating an electrical hazard due to leakage is minimized.

A tubularceramic member 36 is received in the insulative Washer 34 so that it is aligned with thevalve stem 12. The frusto-conical shell 22 is truncated near its apex and anotherinsulative washer 40` is affixed within anaperture 42 formed therein. Thewasher 40 is forcibly seated and retained within theannular shoulder 44 so that it cannot be easily removed and provides a goodseal. The ceramic -member 36 is forced through and terminates in thewasher 40. A good seal is therefore also provided about theceramic member 36, to prevent leakage. It is apparent that a discharge path is provided from thecan 10 through thevalve stem 12, through theceramic member 36.

Anelectrical heating element 46 is placed about and preferably in contact with theceramic member 36 in such a manner as to effect an even distribution of heat about the periphery of the entire length of theceramic member 36. Theheating element 46 is preferably fabricated of Nichrome or similar high heat intensity material so that efficient rapid heating is provided. Theconductors 48 and 50 are connected in the following manner to complete an effective operative circuit:

Conductor 48 is connected, as at 49, to a ring portion 51 of abimetallic thermostat 52, which ringed portion is rigidly sandwiched inbetween an insulative washer 35 and the flush surface resulting from the precast union of washer 34 and the top of the boss 26. At the upper portion (as shown) of thethermostat 52 there is aixed acontact 53 which in its normal position physically touches anothermating contact 54 which is connected to theupper terminus 58 of theheating element 46. Thelower terminus 59 of theheating element 46 is connected, at 68, to aterminal 66 of a gravity operated switch 62, which may be a mercury switch. Theother terminal 67 of the switch 62 is connected, as at `60, to theconductor 50 to complete the operative electrical circuits.

The switch 62 is aixed within theshell 22 rso that the switch 62 is normally open. It may be easily glued and/or taped, -as withtape 64, to the lboss 26 in proper position prior to inserting thebase 24. It will be apparent that upon inverting the aerosol can 10, the pool of mercury 70 (in the event the switch 62 is a mercury switch) will move to a position so as to electrically bridge theterminals 60 and 66 to energize theheating element 46. Theconductors 48 and 50 may be therefore permanently connected to an electrical energy source if desired, and the heating element will not be energized until the aerosol can 10, or theheating unit 20, is inverted to close theterminals 60 and 66.

An electrically insulative sleeve 75 is preferably positioned about theelectrical heating element 46 to prevent misalignment thereof and to further direct heat therefrom to theceramic member 36. A central passage in the ceramic :member 36 includesperpendicular paths 74 and 76 which have cross sections which may be cruciform in shape, star-shaped, liuted, corrugated or spiraled to provide optimal heat dispersement throughout and within the ceramic member. The exterior surface of theceramic member 36 may be formed in the same manner, if desired.

In operation, the user places theheating unit 20 on thevalve stem 12 of the aerosol can 10, either by force fitting it or, if the valve stem is threaded, as illustrated, by threadably engaging thelower portion 30 of the passage through the boss 26 with the threads of the valve stem. As noted above, theelectrical conductors 48 and 50 may be left connected to a conventional electrical outlet or receptacle, and the normally open gravity switch 62 will prevent current flow through theheating element 46. When ready to use, the aerosol can is simply inverted and nger pressure is applied to theheating unit 20, to operate thevalve stem 12, in the well known manner. Upon inverting the aerosol can 10, the gravity contact of the switch 62 will bridge theelectrical terminals 60 and 66 thereby closing the electrical circuit so that current flows through theheating element 46. The contents discharged through thevalve stem 12 to the passage in the ceramic member 36- will be heated as it passes through thepassages 74 and 76 in theceramic member 36.

Thethermostat device 52 included in the above described circuitry precludes inadvertent or deliberate overheating of theheating element 46. The bimetallic material on heating due to current flow through theheating element 46 will bow, in the well known manner, to opencontacts 53 and 54 to thereby prevent further current flow through the circuit includingheating element 46. When I the bimetallic material cools,contacts 53 and S4 will again close. It may therefore be seen that if theheating unit 20, or an aerosol can with the unit affixed is accidentally tipped over and left in an inverted position, 4theheating element 46 would heat up, but thethermostat 52 would prevent it from overheating to the extent of damaging theheating unit 20.

A further safety element has been combined with theheating unit 20 in the form of a dual fused male electrical plug of a conventional variety. The plug 80 consists of low amperage fuses 81 and 82 electrically connected in series withconductors 48 and 50 respectively between male prongs 83 and 84 respectively of the plug '80. A plug of this type is designed to permit only a low amperage current, and if a short circuit should develop, the fuse material will immediately melt to prevent electrical shock to the user. Theheating unit 20, of course, is thereafter inoperable until the plug 80 is replaced, but this is of minor importance when compared to the protection it affords a user in the event a short circuit should develop.

In FIGURE 3, theheating unit 20 is illustrated affixed to an aerosol can 10 having a horizontally orientedvalve stem 86. Avalved button 85 which, in some cases, may be rotatable, maybe provided to operate the aerosol valve (not shown) to discharge the contents of the can. Most horizontally oriented valve stems have a cross sectional shape that is either rectangular or semicircular.

As is partially seen in FIGURE 3 and as shown in more detail in FIGURES 4, 5 and 6, anadapter 90` ts over the end of a horizontally oriented valve stem, such as valve stern 86, and is precluded by the pressurized contents from being forced from and olf of the valve stern by an integrally formedring 96 which slips over the shoulder portion of the valve assembly.

The adapter is preferably of a resilient type material, such as plastic, and has ashank 91, a taperedportion 92, an annularly disposed barrel or stemportion 93 and anintegral retaining ring 96. Acentral passage 95 is formed through thestem 93 and intersects amain cavity 97 which is preferably semicircular in shape, formed in theshank 91. Thestem portion 93 may be threaded, in the manner described above, for use with a threaded valve stem. A number ofannular serrations 98 are formed in the wall of thecavity 97 and a rectangular shapedcavity 99 separates themain cavity 97 from thepassage 95. With this construction, it is found that a valve stem which is semicircular in cross section will abut the outer most wall ofrectangular cavity 99, and one which is rectangular in cross section will extend beyond the semicircularmain cavity 97 and into therectangular cavity 99. A good seal is therefore provided to prevent escape or leakage of the contents of the can as it is being discharged. The adhesive nature of the resilient material and theannular serrations 98 which function as fingers to grip a valve stem cooperate to provide a good seal about horizontally oriented valve stems. Thestem 93 is angularly disposed to prevent actuation of the gravity operated switch 62 while the aerosol can is setting in its normal upright position. When the aerosol can is tilted and the aerosol valve operated, the contents are heated during discharge through theceramic member 36, in the manner described above.

It will thus be seen that the objects set forth above among those made apparent from the preceding description, are eiciently attained and, since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the -above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention, which, as a matter of language, might be said to fall therebetween.

Now that the invention has been described, what is claimed as new and desired to be secured by Letters Patent is:

1. A heating attachment for use with aerosol cans having an aerosol valve with a valve stem to heat the contents thereof as it is discharged from lsaid cans comprisinlg: an adapter having a ring adapted to be afhxed to an aerosol can for securing said heating attachment to said can, a body portion having a valve stem cavity therein, said valve stem cavity having a plurality of serrations forming gripping teeth formed in its wall and a chamber adapted to receive the end of said valve stem to seal it therein, and a nozzle integrally formed with said body portion and angularly disposed substantially horizontally therewith; a heating device including a base having an aperture which is adapted to receive and to retain said nozzle therein; a tubular member dening a discharge passage having one end sealed within said aperture; a hollow shell athxed to said base and to the opposite end of said tubular member so as to form a sealed chamber therein; electric heating means adapted to heat said tubular member enclosed within said chamber; a source of power connected to said electric heating means; gravity operated switch means; and a thermostat, said switch means and said thermostat being enclosed within said chamber and serially included in the connections between said heating means and said source of power and operable to control the initial energization of said heating means and to prevent it from overheating.

2. A heating attachment for use with aerosol cans having an aerosol valve with a valve stem to heat the contents thereof as it is discharged from `said cans comprisimg: an adapter having a ring adapted to be atixed to an aerosol can for securing said heating attachment to said can, a body portion having a valve stem cavity therein, said valve stem cavity having a plurality of serrations forming gripping teeth formed in its wall and a chamber adapted to receive the end of said valve stem to seal it therein, and a nozzle integrally formed with said body portion and angularly disposed substantially horizontally therewith; a heating device including a molded base having an enlarged end, an upstanding member integrally formed with said end and an aperture extending through said end and said upstanding member which is adapted to receive and retain said nozzle therein; sealing means having an aperture therein molded into the upstanding member at its end during the molding of said base to provide a leakproof seal; a tubular member defining a discharge passage having one end sealed within said aperture in said sealing means; a hollow shell aixed to said enlarged end of said base and to the opposite end of said tubular member so as to form a sealed chamber therein; electric heating means disposed about said tubular member; a source of power; a pair of conductors for connecting said heating means to said source of power, said pair of conductors extending throw-gh said base and being molded therein during the molding of said base to provide a leakproof seal; a gravity operated switch aixed to said upstanding member in a fashion such that it is normally open and will close when tilted to a predetermined angular position; and a thermostat, said switch and said thermostat being enclosed within said chamber and serially included in the connections between said heating means and said source of power and operable to control the energization of said heating means and to prevent it from overheating.

3. A heating attachment, as claimed in claim 2, further including plug means affixed to one end of said pair of conductors including short circuit protection means for disconnecting said heating means from said source of power in the event a short circuit develops.

References Cited UNITED STATES PATENTS 2,777,916 1/ 1957 Cooper 200-115 3,069,528 12/1962 Gardner 219--280 3,098,925 7/1963 Fouts 219-214 3,116,403 12/1963 Carter 219-301 3,144,174 8/ 1964 Abplanalp 239-135 ANTHONY BARTIS, Primary Examiner.

U.S. CI. X.R.

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