US 3839614 A
A control switch for conditioning an appliance having multiple operating modes to operate at a higher than normal line voltage prevents inadvertent operation in modes which would exceed the ratings of the appliance by automatically limiting movement of the appliance mode switch when the higher line voltage selection is made. Provision is made for unambiguously identifying the line voltage selected and the operating mode of the appliance at the higher line voltage.
Description (OCR text may contain errors)
United States Patent 1 Saganowski et a].
[4 1- Oct. 1, 1974 1 APPLIANCE CONTROL SYSTEM  Inventors: Mieczyslaw Saganowski, Lititz;
Frank W. Bostick, Lancaster, both of Pa.
 Assignee: Schick Incorporated, Lancaster, Pa.  Filed: Mar. 16, 1973 21 Appl, No.: 342,095
 US. Cl. 200/321, 200/157  Int. Cl. H0lh 3/20  Field of Search... 200/157, 50 C, 61.85, 172 R, 200/167 R, 16 R, 169 R, 60, 42 R; 74/483 R;
 References Cited UNITED STATES PATENTS 3,548,136 12/1970 Frenzel 200/157 3,766,352 10/1973 Bigley et a1. 200/157 X D226,510 3/1973 Benty et al. D86/10 F OTHER PUBLICATIONS The Clairol Air Brush, 1971, copy 200/157, pp. 1-5 and 12 included.
Primary ExaminerRobert K. Schaefer Assistant ExaminerWilliam J. Smith 5 7 ABSTRACT A control switch for conditioning an appliance having multiple operating modes to operate at a higher than normal line voltage prevents inadvertent operation in modes which would exceed the ratings of the appliance by automatically limiting movement of the appliance mode switch when the higher line voltage selection is made. Provision is made for unambiguously identifying the line voltage selected and the operating mode of the appliance at the higher line voltage.
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1 APPLIANCE CONTROL SYSTEM BACKGROUND OF THE INVENTION The present invention relates in general to control switches, and more particularly to control switches which prevent appliances capable of operating in cer' tain operating modes at increased line voltages from being damaged by inadvertent exposure to increased operating voltages in their other operating modes.
With the present trend toward increased foreign travel the need has arisen for portable appliances operable from both the 120 volt line voltage prevalent in the United States and North America, and from the higher 220 volt line voltage prevalent in Europe and much of the rest of the world. While this capability can invariably be obtained by the inclusion of dual voltage circuitry and additional electrical components within such appliances, it is often possible to operate a 120 volt appliance having multiple operating modes in one or more of its lower wattage modes on 220 volts without additional circuitry.
. For instance, appliances such as hair dryers and hair styling combs which utilize multiple resistance heating elements are often capable of operating on a higher line voltage in thier low-wattagelow-heat modes without exceeding the ratings of the selected heating elements. Operation in this manner, while not providing the low heat levels available at the lower line voltage, has the advantage of not increasing the cost of manufacture of the appliance, and is therefore ideally suited for use in appliances which will only occasionally be operated on the higher line voltage.
While an appliance may be capable of operating in a low-wattage mode at an increased line voltage, it will not normally be capable of so operating in its highwattage mode without exceeding the ratings of its resistance heating elements. Thus, it is highly desirable that some form of protection be incorporated within the appliance to prevent inadvertent operation at a high line voltage in a high-voltage mode. Preferably, this protection shouldbe in the form of a user-actuated control which when set for a high line voltage prevents the ap-' pliance control switch from selecting high-wattage operating modes, and which provides an unambiguous indication of the supply voltage conditioning of the appliance. Then, all the user need do is make a voltage selection; the appliance control switch being automatically interlocked to preclude operation in a mode which would cause damage to the appliance.
SUMMARY OF THE INVENTION Accordingly, it is a general object of the present invention to provide a new and improved control switch for an appliance operable from multiple supply voltages.
It is a more specific object of the present invention to provide a new and improved control switch for an appliance operable from multiple supply voltages which prevents the appliance from being inadvertently operated in a mode wherein the ratings of the appliance are exceeded.
It is a still more specific objectof the present invention to provide a new and improved control switch for an appliance operable from a low line voltage and having at least one low-wattage operating mode capable of operation at a high line voltage, and at least one highwattage operation mode not so capable, which prevents damage to the appliance from inadvertent operation at said high line voltage in said high-wattage mode.
It is another specific object of the present invention to provide a user-actuated control switch which condi tions an appliance for operation from a selected voltage and provides a positive indication of the voltage selected.
The invention relates to a control switch for an appliance operable in first and second different modes from a first supply voltage, and operable in the first mode and not in the second mode from a second supply voltage. The control switch comprises a multiple position mode switch having at least first and second switch positions corresponding to the first and second operating modes, respectively, and a voltage selection member having a first position wherein the mode switch is free to enter the first and second positions, thereby conditioning the appliance for operations from the first supply voltage, and a second position wherein the slide switch is blocked from entering the second position, thereby conditioning the appliance for operation from the second supply voltage.
The invention further relates, in an appliance operable from first and second different supply voltages and having a multiple position control switch wherein first and second ones of the positions provide first and second different operating modes at the first supply voltage, respectively, and a first operating mode only at the second supply voltage, it being undesirable to operate the appliance with the control switch in the second position at the second supply voltage, to the improvement comprising operating voltage section means, userpositionable to a first position to condition the appliance for operation at the first voltage, and to a second position to condition the appliance for operation at the second voltage by preventing the control switch from being positioned in the second position.
BRIEF DESCRIPTION OF THE DRAWINGS The features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The invention, together with the further objects and advantages thereof, may best be understood by reference to thefollowing description taken in connection with the accompanying drawings, in the several figures of which like reference numerals identify like elements, and in which:
FIG. 1 is a side elevational view of a hair styler appliance having multiple operating modes and incorporating a control switch constructed in accordance with the invention.
FIG. 2 is an enlarged front elevational view showing the control switch of FIG. 1 in its volt position.
FIG. 2A is an enlarged front elevational view showing the control switch of FIG. 1 in its 220 volt position.
FIG. 3 is a cross-sectional view of the control switch taken along lines 3-3 of FIG. 2.
FIG. 4 is a cross-sectional view of the control switch taken along lines 4-4 of FIG. 3.
FIG. 5 is a cross-sectional view of the control switch taken along lines 5-5 of FIG. 4.
FIG. 6 is an exploded perspective view of the individual elements of the illustrated control switch.
FIG. 7 is a schematic diagram of the electrical circuitry of the hair styler appliance of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT In the accompanying drawings, the invention is shown as incorporated in a portable hair styling appliance 10, which is preferably similar in design and construction to that described in the copending application of Doyle et al., Hair Styling Appliance Ser. No. 297,019 Filed Oct. 12, 1972 and assigned to the present assignee.
Referring to FIG. 1, the air styling appliance is seen to comprise upper and lower housing sections 11 and 12, respectively, which narrow into a grip-like handle portion at one end and widen into a head portion adapted to receive a removable comb attachment 13 at the other end. An air intake 14 comprising a plurality of slot-like openings in sections 11 and 12 is provided to allow an internal fan (not shown) and a multiple section heating element (not shown) to produce a heated air stream around comb attachment 13.
The operation of the hair styling appliance is controlled by means of a novel control switch 15 is constructed in accordance with the invention. As shown in FIG. 1, control switch 15 is located on the handle portion of the appliance and has three positions; a highwattage or DRY position providing high heat output for drying hair, and OFF position, and a low-wattage or STYLE position providing a low heat output for shaping premoistened hair.
Referring now to FIG. 2, control switch 15 is seen to comprise a thumb-operated slide switch 16 which includes a useraccessible actuator stem 17 extending through a rectangular aperture 18 formed between the two housing portions 11 and 12. For reasons of appearance, a slidably mounted masking plate 19, of opaque plastic or other suitable material, overlies switch 16, the actuator stem 17 of slide switch 16 extending therethrough for access by the user. When switch 16 is actuated, as by moving stem 17 to the right or to the left, mask 19 moves with the actuator stem so that the body of the switch is always hidden from view.
Indicia corresponding to the 120 volt operating modes of the appliance are molded into the case at appropriately spaced positions above aperture 18, and by positioning the stem of switch 16 in line with these positions it is possible to operate the appliance in either high or low heat modes, or by positioning the stem at OFF, to not operate the appliance at all. The designation 120 adjacent the DRY position of the switch indicates that the three indicia above aperture 18 relate to 120 volt operation of the appliance.
As is typical for many multiple-mode electrical appliances of its type, hair styler 10 is capable of operating in its low-wattage or STYLE operating mode on an increased line voltage of 220 volts without damage to its internal heating elements. This is because the heating element switched into circuit in the STYLE mode is of a sufficiently high resistance so that the resulting current flow does not exceed the heat dissipation rating of the element or the heat handling capabilities of the appliance. However, this is not true for operation in the high-wattage or DRY mode, since the resistance of the heating element switched into the circuit is substantially lower and the resulting current flow would exceed the ratings of the element and cause permanent damage to the appliance.
Therefore, and in accordance with the invention, the appliance control switch 15 incorporates a voltage conditioning slider 20 adapted to extend from a retracted or volt position shown in FIG. 2 to an extended or 220 volt position shown in FIG. 2A. The actual extension and retraction of the slider is facilitated by a useraccessible tab 21, which extends through aperture 18 to an extent sufficient for actuation by the user. As il lustrated in FIG. 2A, in its extended position the tab 21 of slider 20 occupies the 120 volt DRY position of actuator stem 17, thereby blocking or preventing slide switch 16 from being placed in that position. Thus, when slider 20 is properly positioned by the user, inadvertent damage to the appliance from operation in its high-wattage or DRY mode from a 220 volt source is effectively precluded.
It will be appreciated that when operating on 220 volts in the low-wattage 120 volt STYLE mode the amount of heating actually obtained is actually comparable to that obtained when operating on 120 volts in the high-wattage DRY mode. Accordingly, the control switch of the invention provides for redesignation of the operating mode by means of indicia OFF and DRY appropriately positioned on slider 20. When slider 20 is extended as in FIG. 2A these indicia are exposed to clearly indicate the new function of the mode switch 16. The indicia 220 v indicate that the appliance is conditioned for 220 volt operation with slider 20 in the illustrated extended position. In the retracted position of slider 20 as shown in FIG. 2, the indicia on the slider are completely hidden by housing section 12 so that the 120 volt indicia again apply. In practice. slider 20 may be of a bright contrasting color to clearly indicate the abnormal 220 volt operating conditions of the appliance when the slider is extended.
Referring to FIG. 3, the slide switch is seen to be held in position by a slot molded into the bottom half 12 of the appliance housing. The actuator stem 17 of switch 16 is seen to extend through aperture 18 for access by the user. Also, the actuator tab 21 of slider 20 is seen to extend through the same aperture and the slider is seen to be held in position by the aforementioned slots in the housing. The masking plate 19 is disposed between slider 20 and the body of switch 16. A flat spring 22 is provided below the masking plate for the purpose of providing friction against inadvertent movement of slider 20.
The relationship between the line voltage conditioning slide 20 and the control stem 17 of switch 16 can better be seen by reference to FIG. 4. There, slider 20 is seen to overly the masking plate 19, and as such is free to slide over plate 19 along a path perpendicular to the path of stem 17. Switch 16 is held in position against masking plate 19 by means of appropriately spaced slots 23 molded into housing section 12 which engage ears on either side of the switch.
As shown in FIG. 5, slider 20 is held in position by means of spring clip 22 which is retained by slots 23 and forced to bear against the rear surface of the slider. This imparts a controlled friction to slider 20 such that the slider is more readily retained in a user-selected position.
The interaction between the various members of the control switch can be seen by reference to FIG. 6, which shows these elements in an exploded relationship. The user-actuated voltage conditioning slider 20 is seen to overly spring clip 22, which is positioned beside the masking plate 19. The stem 17 of switch 16 extends through plate ]l9 to a user-accessible location.
As stated previously, limitations in the electrical circuitry of hair styler l0 preclude operation of the styler at 220 volts in the high-heat or DRY mode of operation. This can be appreciated by reference to FIG. 7, which is a schematic diagram of the electrical circuitry of the hair styling appliance. Referring to FIG. 7, an AC current source, as represented by an AC line cord 30, is connected to the transfer contact of one section of mode switch 16, a three-position two-section slide-type switch. The other side of the AC line is connected by means of a thermal safety switch 32 to one end terminal of an electrical heating element 33, which comprises four individual resistance sections 34-37. The other end contact of heating element 33 is connected to the remaining section 38 of mode switch 16 and to the lowheat contact of the first section of the switch. Resistive heating element 33 includes three taps 39-41 between sections 34 and 35, 35 and 36, and 36 and 37, respectively. Taps 39 and 41 are connected to the anodes of a pair of rectifiers 42 and 43, respectively, and the cathodes of these rectifiers are connected together and to one terminal of a DC fan motor 44. The remaining terminal of motor 44 is connected directly to tap 40 on heating element 33. Tap 41 is also connected to the high-heat contact of switch section 31, and the highheat contact of switch section 38 is connected directly to the other side of the AC line.
In operation, when mode switch 16 is positioned for high-heat or DRY operation, one side of the AC line is connected to both of the end terminals of the resistive heating element 33. The other side of the AC line is connected to tap 41', thus connecting segment 37 in parallel with the series combination of segments 34-36, and thus developing a voltage across segments 35 and 36 for application to motor 44. Diodes 42 and 43 rectify the alternating current developed across segments 35 and 36 for the purpose of supplying a direct current to motor 44. Thus, the low-heat mode allows full line current to be applied across section 37 of heating element 33, and allows sections 34-36 to operate in series while developing a suitable alternating current for rectification and subsequent application to fan motor 44.
When mode switch 16 is positioned for low-heat or STYLE operation, the AC line is connected across all four sections 34-37 of heating element 33. Since the AC line is not connected to any one of taps 39-41, all four sections of the heating element are in series-circuit relationship and less current flows through the heating elements than did in the DRY operating mode. However, as before fan motor 44 receives its operating power by way of the voltage drop developed across sections 35 and 36 of heating element 33.
From the foregoing discussion, it will be appreciated that upon doubling the voltage applied at line cord 30, an increased current will flow through the various sections of heating element 33. In the case of high-heat or DRY operation at 220 volts, approximately twice as much current will flow through element 37, and the increased dissipation therein as a result of the increased current flow will exceed the heat dissipation capabilities of that element. However, in the low-heat operating mode, the AC line is applied across elements 34-37 6 in series, and the resulting increase in dissipation is not so great as to exceed the capabilities of the entire heating element 33. Thus, by preventing mode switch 16 from being positioned for high-heat operation when the appliance is being operated from a 220 volt source the control switch of the present invention prevents inadvertent damage to the appliance.
A novel appliance switch has been shown and described which prevents a multi-mode appliance from being inadvertently operated at increased line voltages in modes which would result in damage to the appliance. This makes it feasible to use the appliance in foreign countries on higher line voltages, thereby greatly increasing the usefulness of the appliance to the user who makes frequent foreign trips. The control switch is simple and economical in design and construction, and can therefore be incorporated in an appliance with little added cost. This makes the switch particularly attractive to the high-volume low-profit-margin consumer appliance market, wherein the expense of obtaining dual voltage operation by inclusion of additional circuitry would not normally be justified.
It will be appreciated that the control switch of the invention can be used in other types of appliances in tended for other purposes. Furthermore, other types of switches, such as rotary switches, may be used in conjunction with other forms of voltage conditioning means for preventing operation at higher or lower voltages in higher-or lower-wattage operating modes.
While a particular embodiment of the invention has been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made Without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.
I. In an appliance operable in first and second modes from a first range of supply voltages, and operable only in said second mode from a second range of supply voltages, and having a housing including a switch access aperture, a control switch assembly comprising, in combination:
means including a multiple position slide switch having at least first and second positions for selectively conditioning said appliance to operate in said first and second operating modes, respectively, said switch having an actuator stem projecting therefrom;
means for mounting said mode selection slide switch within said housing with said actuator stem extending through said switch access aperture to enable said switch to be user-positioned in either said first or second mode selection positions;
voltage selector means comprising a slide member slidably mounted within said housing and having a user-accessible actuator tab extending through said switch access aperture for selectively conditioning said appliance for operation from either said first or second range of supply voltages, said actuator tab blocking said switch actuator stem from said first mode selection position when said slider is positioned to condition said appliance for operation from said second range of supply voltages.
2. An appliance control switch as defined in claim 1 wherein said voltage selection slide member comprises a generally planar slider constrained to reciprocate along a path perpendicular to the path of said mode selection slide switch actuator stem, and wherein said actuator tab projects from one edge and extends perpendicular to the outside face of said slider.
3. An appliance control switch as defined in claim 2 wherein said actuator tab is substantially identical in size to said stern of said mode selection slide switch.
4. An appliance control switch as defined in claim 2 wherein said outside face of said voltage selection slider includes indicia indicative of the operating mode selections of said mode selection slide switch when said appliance is conditioned to operate from said second range of supply voltages, acd wherein said indicia appear through said switch access aperture only when said slider is positioned to condition said appliance to operate from said second range of operating voltages.
lection slider within said housing.
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 839 614 Dated October 1 1974 Inventor) Mieczyslaw Saganowski and Frank W. Bostick It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column 1, line 41, "voltage" (second occurrence) should be -wattage-;
Column 3, line 10, "air" should be --hair-;
Column 3, line 22, delete "is";
Column 7, line 12, "acd" should be -and--.
Signed and sealed this 29th day of April 1975.
(SEAL) I Attest:
C. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks FORM P0-1050 (10-69) USCOMM-DC 60376-P69 w u.s. GOVERNMENT PRINTING OFFICE I989 o-ass-ssa.
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,839,614 Dated October 1, 1974 Inventor) Mieczyslaw Saganowski and Frank W. Bostick It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column 1, line 41, "voltage" (second occurrence) should be -wattage;
Column 3, line 10, "air" should be -hair--; Column 3, line 22, delete "is";
Column 7, line 12, "acd" should be -and-.
Signed and sealed this 29th day of April 1975.
(SEAL) I Attest:
C. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks FORM P0-1050 (10-69) USCOMM-DC 60376-F'69 ".5. GOVERNMENT PRINTING OFFICE l99 O-866-3S