TECHNICAL FIELD

The present invention relates generally to dispensing apparatus, and more particularly to a dispenser that dispenses a heated post-foaming gel.

BACKGROUND ART

Shaving lather dispensers that dispense heated shaving lather have been known for some time. For example, Rossi U.S. Pat. No. 3,335,910 discloses a heatable shaving lather dispenser including a housing, an elongate heat conductive block and a heater disposed in a channel in the block. A lather carrying duct extends through the block in heat transfer relationship with the heater and a first end of the duct is in fluid communication with an aerosol container. A second end of the duct has a selectively operable valve disposed therein. The duct is maintained at container pressure and the valve is actuable to dispense heated lather into the hand of a user.

Wilkins U.S. Pat. No. 3,498,504 discloses a heated aerosol lather dispenser having a casing, a lather-containing pressurized aerosol container retained in the casing and a head disposed above the aerosol container. The head includes an electrically heated block having a passage therethrough in fluid communication with the lather in the container. A valved outlet is provided between the passage and a discharge spout and is selectively actuable to dispense lather.

Post-foaming shaving materials have been developed which are designed to be dispensed in gel form. The post-foaming shave gel may then be applied to the skin of the user and, in the course of such application, the post-foaming shave gel is worked in a fashion that causes the gel to foam. While such gels are effective to prepare the skin of the user for shaving, it is believed that the skin preparation effect and/or shaving comfort are enhanced when the gel is heated and then applied to the skin. However, known dispensing devices, such those disclosed in the Rossi and Wilkins patents described above, are not designed specifically for use with such gels, and, in fact, use of such dispensers and can result in undesirable premature foaming of the gel.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, an apparatus for dispensing a heated gel includes a housing having a recess therein, a coupling assembly disposed in the housing and adapted to retain a pressurized gel container in the recess and a heater assembly disposed in the housing. The heater assembly includes a heater selectively operable to develop heat and a heat exchanger in heat transfer relationship with the heater and having a chamber for receiving a quantity of gel. The heater assembly further includes a first valve in fluid communication with a first portion of the chamber and operable to expose the chamber to pressurized gel and a second valve in fluid communication with a second portion of the chamber and operable to allow dispensing of gel without substantial foaming.

A further alternative aspect of the present invention comprehends a combination of a dispensing apparatus and a can of pressurized shaving gel. The can includes a can valve and a coupling cap having a circumferential flange. The dispensing apparatus includes a housing having a recess therein wherein the can is disposed in the recess, a coupling assembly disposed in the housing and engaging the circumferential flange of the coupling cap and a heater assembly disposed in the housing. The heater assembly includes a heater selectively operable to develop heat and a heat exchanger in heat transfer relationship with the heater and having a chamber. The heater assembly further includes a first valve in fluid communication with a first portion of the chamber and engageable to move the can valve and the first valve to open positions to expose the chamber to pressurized shaving gel and a second valve in fluid communication with a second portion of the chamber and operable to allow dispensing of gel without substantial foaming.

Other aspects and advantages of the present invention will become apparent upon consideration of the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1

is an isometric view of an apparatus according to the present invention;

FIG. 2

is a partial sectional view of the apparatus of

FIG. 1

together with a can of pressurized shave gel taken generally along the lines

2

—

2

of

FIG. 1

;

FIG. 3

is an exploded and enlarged isometric view of a portion of the apparatus of

FIG. 1

;

FIG. 4

is an exploded isometric view of the rear of the apparatus of

FIG. 2

;

FIG. 5

is an exploded and enlarged isometric view of a portion of the apparatus of

FIG. 4

;

FIG. 6

is an enlarged isometric view of the underside of a collar portion illustrating a can coupling assembly;

FIG. 7

is a circuit diagram of a control circuit used in the apparatus of

FIGS. 1-5

;

FIG. 8

is an isometric view of an underside of the heat exchanger of

FIGS. 2-5

;

FIG. 9

is a sectional view taken generally along the lines

9

—

9

of

FIG. 8

;

FIG. 10

is an exploded isometric view of various components of

FIGS. 2-5

looking down from above;

FIG. 11

is an exploded isometric view of the components of

FIG. 10

looking up from below;

FIG. 12

is an enlarged, fragmentary, full sectional view illustrating the engagement of the coupling cap with the coupling cover;

FIGS. 13 and 14

are full sectional views of the collar portion and upper portion, respectively; and

FIG. 15

is a full sectional view of an alternative embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to

FIGS. 1

,

2

and

4

, a dispensing apparatus

10

according to the present invention includes a housing

12

having a main body portion

14

joined in any suitable fashion, such as by screws, to a collar portion

16

and an upper portion

18

. The main body portion

14

is further joined by screws or any other suitable fastener(s) to a base portion

20

. The portions

14

,

16

,

18

and

20

are fabricated of any suitable material, such as polycarbonate.

The housing

12

defines a recess

22

(

FIG. 2

) within which may be disposed a pressurized can

24

containing shaving gel. The post-foaming shave gel preferably is of the type disclosed in Szymczak U.S. Pat. No. 5,858,343, owned by the assignee of the present application and the disclosure of which is incorporated by reference herein.

Referring also to

FIG. 5

, the can

24

includes a coupling cap

26

carried on an upper annular rim

28

. A series of three inwardly-extending tabs (not shown) are carried by the cap

26

at a lower end thereof and the tabs are disposed below the rim

28

to maintain the cap

26

on the can

24

. The coupling cap

26

includes an annular flange

30

and surrounds a conventional resilient spring-loaded aerosol valve

32

disposed in the can

24

. Referring to

FIGS. 2

,

4

and

6

, the collar portion

16

includes a coupling assembly

34

comprising a coupling ring

36

that is biased toward an engaged position by a spring

38

. The coupling ring

36

is disposed between and restrained against axial movement by an upper wall

37

of the main body portion

14

and a wall

39

of the collar portion

16

(FIG.

2

). The coupling ring

36

may be moved against the force of the spring

38

toward a disengaged position by pushing on a button

40

extending outwardly through an aperture in the collar portion

16

. When the can

24

is inserted upwardly in the recess

22

, the annular flange

30

engages a sloped surface

42

(FIG.

6

), thereby displacing the coupling ring

36

toward the disengaged position until an edge

44

of the sloped surface

42

reaches an outer edge

45

of the annular flange

30

. At this point, the edge

44

of the sloped surface

42

rides over the edge

45

and the coupling ring

36

snaps under the force of the spring

38

into the engaged position whereby the portion of the coupling ring

36

carrying the sloped surface

42

is disposed in interfering relationship with the annular flange

30

. In addition, also referring to

FIG. 12

, as the can

24

is being pushed upwardly, a tapered outer surface

47

of a central portion

46

of the coupling cap

26

contacts a sloped surface

51

of a coupling cover

52

that is resiliently biased by a spring

54

. The central portion

46

of the coupling cap

26

is connected to an outer wall

48

of the cap

26

by a series of four fingers

50

(two of which are visible in FIGS.

2

and

12

). Preferably, the sloped surface

51

forms an angle relative to a horizontal line in

FIG. 12

, which is 1-2 degrees less than the included angle between the tapered outer surface

47

and a horizontal line. Also a circumferential groove

53

is disposed in an upper surface of the central portion

46

, which results in a degree of flexibility of an upper part

55

of the portion

46

. Thus, as the can

24

is pushed upwardly and the force exerted by the spring

54

is overcome, the upper part

55

of the tapered outer surface

47

is compressed and seals against the sloped surface

51

. In addition, the pressure exerted on the portion

46

causes the can valve

32

to open. However, the sealing of the upper part

55

against the sloped surface

47

prevents gel from escaping into the space surrounding the central portion

46

.

Thereafter, when it is desired to remove the can

24

from the recess

22

, a user need only depress the button

40

to cause the coupling ring

36

to move to the disengaged position whereupon the spring

54

, the resilient can valve

32

and a further spring-loaded resilient valve described hereinafter urge the can

24

downwardly out of the recess

22

.

Referring to

FIGS. 2-5

and

12

, the coupling cover

52

includes a series of four legs

56

having outwardly directed flanges

58

. The coupling cover

52

is disposed in a ring

60

such that the flanges

58

engage a stepped inner surface of the ring

60

. The ring

60

and the coupling cover

52

are disposed in a stepped counterbore

64

in a mounting plate

66

such that an outer flange

62

of the ring

60

abuts a shoulder

68

(

FIG. 2

) partially defining the counterbore

64

. An o-ring

69

provides a seal between the coupling cover

52

and the ring

60

.

FIG. 15

illustrates an alternative embodiment wherein structures common to

FIGS. 12 and 15

are assigned like reference numerals. In the embodiment of

FIG. 15

, the coupling cover

52

, the spring

54

, the ring

60

and the o-ring

69

are replaced by a coupling cover

52

a

that is retained in the stepped counterbore

64

. The coupling cover

52

a

is axially movable a short distance owing to a clearance provided between the walls defining the counterbore

64

and a circumferential flange

52

b

of the coupling cover

52

a.

This embodiment relies upon the resiliency of the can valve

32

and the further resilient valve described hereinafter to eject the can

24

from the recess

22

.

Referring again to

FIGS. 2-5

, the mounting plate

66

further includes a cylindrical hollow insert

70

that is retained by any suitable means in a bore

72

. A plunger

74

of a pressure relief valve

76

is disposed together with a spring

78

in the insert

70

. The insert

70

is open at both ends and is in fluid communication with an exit tube

80

.

Referring to

FIGS. 2-5

,

10

and

11

, a heater assembly

90

is disposed atop the mounting plate

66

. The heater assembly includes a heat exchanger

92

, a heat distributor plate

93

disposed atop the heat exchanger

92

, an electrical resistance heater

94

disposed atop the heat distributor plate

93

and a retainer clip

96

that maintains the elements

92

-

94

in assembled relationship. The heat exchanger

92

and distributor plate

93

are fabricated of any suitable heat conductive materials, such as copper. The resistance heater

94

preferably comprises a 26 watt resistive element wound on a mica core and is wrapped in electrical insulation. The electrical insulation comprises a resin impregnated with mica wherein the impregnated resin is bonded to a glass cloth. The retainer clip

96

is made of any suitable material, such as stainless steel, and is sufficiently flexible to allow the legs thereof to deform and snap over side walls of the heat exchanger

92

such that raised portions

97

(

FIGS. 10 and 11

) of the heat exchanger

92

reside in apertures

98

in the clip

96

. This interfering fit of the raised portions with the apertures

98

securely fixes the clip

96

and the elements

93

and

94

on the heat exchanger

92

.

Referring also to

FIGS. 8 and 9

, the heat exchanger

92

includes a chamber

100

therein. A first resiliently biased valve

102

is in fluid communication with a first portion of the chamber

100

and a second resiliently biased valve

104

is in fluid communication with a second portion of the chamber

100

. Preferably, each of the first and second valves

102

,

104

comprises a conventional valve used in pressurized aerosol cans. Alternatively, one or more of the valves

32

,

102

and

104

may be of the type disclosed in U.S. Pat. Nos. 4,442,959; 4,493,444; 4,522,318; and 4,532,690. The heat exchanger

92

also preferably includes a folded internal wall

106

(

FIG. 9

) that is also preferably made of copper and that serves to increase the heat transfer ability of the heat exchanger

92

. It is believed that the folded internal wall

106

may assist in mixing the gel in the heat exchanger

92

to reduce the incidence of localized hot spots or cold spots in the gel. The chamber

100

is sized to accommodate approximately five to seven grams, and, more specifically, approximately six grams of shaving gel.

Referring to

FIGS. 2-5

and

8

, a washer-shaped gasket

110

is carried by the plunger

74

and bears and seals against a sealing surface

112

(

FIG. 8

) surrounding an opening

114

in a lower wall

116

(also seen in

FIG. 8

) of the heat exchanger

92

. The plunger

74

is displaceable in a downward direction in response to an undesirably elevated pressure in the chamber

100

to vent material from the chamber out through the tube

80

. The pressure at which this relief action takes place is determined in part by the stiffness of the spring

78

.

A printed circuit board

120

includes an aperture

121

. The printed circuit board

120

is disposed on an electrically insulative carrier

123

such that a tab

122

is disposed in the aperture

121

and further such that the board

120

is engaged and restrained against movement by the tab

122

and a pair of side clips

124

a,

124

b.

The printed circuit board

120

mounts the various electrical components shown in

FIG. 7

for controlling the heater

94

including a surface-mounted temperature switch

126

(

FIGS. 2

,

6

and

11

). With reference to

FIGS. 2

,

10

and

11

, the temperature switch

126

is mounted at an end

128

of the printed circuit board

120

opposite the aperture

121

. The distributor plate

93

includes an extension member

130

that extends outwardly and upwardly and folds back upon itself to surround the end

128

of the printed circuit board

120

, and, more particularly, the temperature switch

126

. A thermal compound may be provided between the distributor plate

93

and the heat exchanger

92

to enhance thermal conductivity therebetween. Preferably, the thermal compound comprises Chemplex 1381 heat sink silicone sold by NFO Technologies, a division of Century Lubricants Co. of Kansas City, Kans. A sheet of electrical insulation

131

is also provided between the extension member

130

and the temperature switch

126

to provide electrical isolation of the switch

126

. The sheet

131

further extends rearwardly between the carrier

123

and the clip

96

. This arrangement ensures that electrical isolation is provided for the printed circuit board

120

and further ensures that the temperature switch

126

is exposed to a temperature representative of the temperature of the heater

94

.

If desired, the distributor plate

93

may be omitted and the heat exchanger

92

may be provided with an extension member like the member

130

.

The mounting plate

66

is secured to an inner enclosure member

140

by any suitable means, such as screws, thereby capturing the heater assembly

90

within the member

140

. In this regard, the carrier

123

includes ribs

135

(

FIGS. 10 and 11

) that fit within slots

137

(

FIG. 11

only) of the member

140

to restrain the various components against substantial movement. A gasket

141

is provided between the heat exchanger

92

and the inner enclosure member

140

to prevent passage of material into the space above the heat exchanger

92

.

The inner enclosure member

140

is mounted for pivoting movement about a pivot axis

142

(

FIG. 3

) within the upper portion

18

of the housing

12

(FIG.

2

). Specifically, as seen in

FIGS. 13 and 14

, the collar portion

16

includes a pair of semicircular recesses

134

that mate with aligned semicircular recesses

136

in the upper portion

18

to form cylindrical bores that accept a pair of axles

138

a

and

138

b

(

FIGS. 3

,

5

,

10

and

11

) of the inner enclosure member

140

. The upper portion

18

of the housing

12

includes an aperture

143

(

FIG. 4

) through which an actuator member

144

of the inner enclosure member

140

extends. Preferably, the inner enclosure member is fabricated using a two-shot molding process wherein a main part

145

of the inner enclosure member

140

is first molded of polycarbonate and thereafter the actuator member

144

is molded onto the main part

145

. Preferably, the actuator member is made of low modulus TPE. Pushing down on the actuator member

144

results in pivoting of the member

140

, the heater assembly

90

and the mounting plate

66

about the pivot axis

142

. This pivoting of the heater assembly

90

with respect to the upper portion

18

causes the second valve

104

to push down on walls

150

of the collar portion

16

surrounding an exit

152

(FIG.

2

), thereby resulting in opening of the second valve

104

and dispensing of heated gel from the chamber

100

.

Molded in the actuator member

144

is a flexible pushbutton

156

having a downwardly depending portion that is engageable with a switch SW

1

(

FIG. 6

) carried by the printed circuit board

120

. First and second lenses

160

and

162

(

FIG. 3

) are molded as part of the member

140

and are adapted to transmit light produced by two light-emitting diodes LED

1

and LED

2

(

FIGS. 2

,

3

and

7

), respectively. Electrical power for the electrical components is supplied over a power cord

163

(

FIGS. 10 and 11

) that extends from the printed circuit board

120

through a bore in the gasket

141

behind the heat exchanger

92

and a power cord cover

164

and outwardly from the main body portion

14

. A grommet

165

is molded as part of the power cord

163

and includes a curved surface

166

(

FIG. 10

) that fits against a correspondingly-shaped end wall of the heat exchanger

92

.

FIG. 7

illustrates the electrical circuitry for operating the heater

94

. Electrical power is applied through first and second thermal fuses F

1

and F

2

to first and second conductors

170

,

172

. Resistors R

1

, R

2

, R

3

and R

4

, diode D

1

, zener diode Z

1

and capacitors C

1

and C

2

provide a stable voltage source of predetermined magnitude for the temperature switch

126

. In the preferred embodiment, the temperature switch

126

comprises a MAX6501 micropower temperature switch manufactured by Maxim Integrated Products of Sunnyvale, Calif. An output of the temperature switch

126

is coupled to a transistor Q

1

suitably biased by resistors R

5

and R

6

. A resistor R

7

and the diode LED

2

are connected in series between the collector of the transistor Q

1

and the conductor

172

. The output of the temperature switch

126

is also coupled to a diode D

2

, which is, in turn, connected to a collector of a transistor Q

2

through a resistor R

8

. The transistor Q

2

includes an emitter coupled to a junction between the resistors R

2

and R

3

. A resistor R

9

and a capacitor C

3

are connected across the base and emitter of the transistor Q

2

. A resistor R

10

is coupled between the base of the transistor Q

2

and a collector of a transistor Q

3

. The collector of the transistor Q

3

is also coupled to the emitter of the transistor Q

2

by a resistor R

11

and the diode LED

1

.

The switch SW

1

has a first end coupled to a junction between the resistors R

10

and R

11

and further has a second end coupled to the conductor

172

. In addition, a diode D

3

is connected between the resistor R

8

and the base of the transistor Q

3

and the latter is further coupled to the conductor

172

by a resistor R

12

. The emitter of the transistor Q

3

is coupled to a control electrode of the triac Q

4

, which in turn further includes main current path electrodes connected in series with the heater

94

between the conductors

170

and

172

.

Industrial Applicability

In operation, the can of pressurized shaving gel

24

is inserted into the recess

22

until the coupling ring

36

snaps into the engaged position as noted above, thereby locking the can

24

in the recess

22

. The power cord for the dispensing apparatus

10

is then plugged into a standard wall outlet (if it is not already plugged in). In this regard, the thermal fuses F

1

and F

2

are positioned on the printed circuit board

120

so that, in the event of a component failure causing the heater to experience a thermal runaway condition, one or both of the fuses F

1

and F

2

disconnects the power from the circuitry on the printed circuit board. In addition, the fuses F

1

and F

2

are disposed on the printed circuit board

120

proximate the resistors R

1

and R

2

so that, in the event that the power cord is plugged into a wall outlet supplying power at other than the

120

rated volts for the unit (such as 252 volts), the resistors R

1

and R

2

develop a magnitude of heat sufficient to cause one or both of the fuses F

1

and F

2

to disconnect the power from the balance of the circuitry on the printed circuit board

120

. Of course, the fuses F

1

and F

2

must be rated and positioned on the printed circuit board so that a 120 volt application of power does not cause inadvertent tripping of the fuses F

1

and F

2

.

Referring to

FIGS. 2 and 6

, once the power cord is plugged in the user may depress the pushbutton

156

, in turn closing the switch SW

1

, whereupon the diode LED

1

is energized by the gating of current through the diode D

1

, the resistors R

1

, R

2

and R

11

and the switch SW

1

. In addition, closing the switch SW

1

turns on the transistor Q

2

. However, the transistor Q

3

and the triac Q

4

are maintained in an off condition while the switch SW

1

is closed so that a user cannot cause continuous energization of the heater

94

by continuously holding down the pushbutton

156

. Thereafter, upon release of the pushbutton

156

, the transistor Q

3

is turned on through the diode D

3

. In addition, upon initial closure of the switch SW

1

, and until the time that the temperature switch

126

detects a first temperature magnitude, such as approximately 130 degrees F., an output TOVER(bar) is in a high state. Therefore, the triac Q

4

turns on and remains on to energize the heater

94

following release of the switch SW

1

owing to the continued on state of the transistors Q

2

and Q

3

and the high state status of the output TOVER(bar). The heater

94

continues to heat until the first temperature magnitude is detected by the temperature switch

126

, whereupon the output TOVER(bar) switches to a low state. Upon this occurrence, the junction between the diodes D

2

and D

3

is pulled low, thereby turning off the transistors Q

2

and Q

3

and the triac Q

4

so that current flow through the heater

94

is interrupted. In addition, the transistor Q

1

is turned on, thereby causing the diode LED

2

to illuminate. In the preferred embodiment, the diode LED

1

is red in color and the LED

2

is green in color.

The dispensing apparatus

10

is designed so that the gel remains above a particular temperature (such as 125 degrees F.) for a period of time (such as 2 minutes) after heating. As should be evident from the foregoing, the temperature sensed by the switch

126

is representative of (but not exactly equal to) the temperature of the gel. Preferably, although not necessarily, the temperature sensed by the switch

126

should remain within a tolerance band of no greater than five degrees F. below the temperature of the gel. Also, the control circuit preferably controls the temperature of the gel to within ±5 degrees F. of a set point of 130 degrees F. Once the temperature switch

126

detects a temperature below a second temperature magnitude, such as approximately 125 degrees F., the output TOVER(bar) reverts to the high state, thereby turning the LED

2

off. The apparatus

10

is thus in a state ready to be actuated by depressing the switch SW

1

again, thereby initiating another heating sequence.

As should be evident from the foregoing, once the pushbutton

156

is depressed and released the heater

94

is energized. During this time the red LED

1

is energized to alert the user that heating is occurring. This operation continues until a certain temperature is reached, whereupon the heater

94

is deenergized and the red LED

1

is turned off and the green LED

2

is turned on. The green LED

2

remains in the energized state informing the user that the gel is ready for dispensing until the temperature sensed by the temperature switch

126

drops below the second temperature magnitude. Significantly, the heater

94

remains deenergized until the pushbutton

156

is again depressed, thereby providing an auto-shutoff feature that contributes to the safety of the apparatus

10

.

Because the heater

94

heats the heat exchanger

92

and the gel through the distributor plate

93

, the heat exchanger

92

and the gel contained therein cannot be heated to a temperature higher than the distributor plate

93

. Also, inasmuch as the temperature switch

126

is closely thermally coupled to the distributor plate

93

, the temperature of the plate

93

is accurately controlled, and the relatively high thermal mass of the plate

93

results in accurate tracking of the gel temperature with the temperature of the plate

93

with only short time lags. Accuracy is further enhanced by the isolation of the temperature switch

126

from the surrounding environment (except for the temperature of the plate

93

). This is achieved by disposing the temperature switch

126

at an end of the printed circuit board

120

remote from the balance of the circuitry carried by the board

120

and providing serpentine electrical connections to the temperature switch

126

. Further thermal isolation is accomplished by surrounding the temperature switch

126

with the extension member

130

. Still further accuracy is afforded by the use of the temperature switch

126

itself, inasmuch as such device has a low thermal mass that does not require significant energy to heat or cool.

It should be noted that the dispensing apparatus

10

is compact yet capable of accommodating various can sizes. This ability is at least partially afforded by the size of the recess

22

and the positive locking of the can

24

therein by the coupling ring

36

. In the preferred embodiment, a wide range of can sizes can be accommodated, such as cans between 0.50 inch and 4.00 inches in diameter and 1.00 inch and 8.00 inches in height, although any can size could be used provided that the dispensing apparatus

10

is appropriately designed to accept such can size.

The present invention comprehends a shave gel heating system that minimizes post-foaming of the gel prior to dispensing thereof. This is achieved by using a post foaming component in the gel formulation (preferably isopentane alone without isobutane) that exhibits a relatively low vapor pressure (as compared with gel formulations not intended to be heated) and by employing a closed heating system that keeps the heated gel under can pressure until the gel is dispensed.

It should be noted that the present invention may be modified by omitting the valve

102

, in which case suitable sealing apparatus evident to one of ordinary skill in the art would be provided between the can valve

32

and the heat exchanger to allow the gel in the heat exchanger to be maintained at can pressure.

Numerous modifications to the present invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is presented for the purpose of enabling those skilled in the art to make and use the invention and to teach the best mode of carrying out same. The exclusive rights to all modifications which come within the scope of the appended claims are reserved.