US 3284611 A
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Description (OCR text may contain errors)
i NOV. 8, 1966 N, LAlNG PORTABLE HAIR DRYERS 2 Sheets-Sheet l Filed April l2 1965 /N VEN IM Nm@ AL/5 LAI/VG Nov. 8, 1966 N. LAING 3,284,611
PORTABLE HAIR DRYERS Filed April l2, 1965 2 Sheets-Sheet 2 37 17% IJ, 55/ f/ 7/ United States Patent O L 1s claims. (l. 21a-37o) This invention relates to portable hair dryers. The application is a continuation in part of my copending application No. 853,596, filed November 17, 1959, now abandoned, and also of my copending application No. 73,931, filed April 14, 1960, now Patent No. 3,177,794, dated April 13, 1965.
The main object of the invention is to provide a compact and simple form of hair dryer. Many hair dryers hitherto in common use have a hand grip which makes the appliance awkward to pack and store. The present invention is based on the concept that the casing for the rotor means of the hair dryer should itself form the hand grip. Now the reason for the prior hair dryers having handles is precisely because their rotor casings are not themselves adapted to form hand grips; this is possibly because the casing cannot readily be grasped or the appliance is too heavy, or because if it were grasped the users hand would foul the air inlet or outlet, or because the weight distribution would tire the user, or because without a handle the air stream cannot conveniently be directed at the users hair, or for some combination of these causes or on account of some other difliculty. It is to be appreciated that in proposing the use of the rotor casing itself as hand grip the invention proposes to provide an appliance free from these drawbacks. Thus it is an object of the invention to provide a hairdryer which, held by its casing as hand grip, is comfortable to grasp and well balanced, which delivers an air jet in a convenient direction when so held and wherein the air inlet and outlet are not likely to be obstructed in normal use.
With these objects in view, the invention provides a hair dryer comprising a casing having top and bottom walls, a rear wall merging into the top and bottom walls and end walls joining the top and bottom walls, the casing defining an inlet and defining an outlet opposite the rear wall extending substantially over the length of the casing between the end walls; motor-driven bladed cylindrical rotor means mounted adjacent the rear wall directly opposite the outlet and also extending substantially over the length of Vthe casing between the end walls; second Wall means defining with the interior surface of the casing bottom wall an outlet duct leading from the rotor means to the outlet; electric heater means in said outlet duct; the rotor means being effective on operation to induce a flow of air into the inlet, through the rotor, through the outlet duct past the heater means and out of the outlet; and the casing formed as hand grip.
In one embodiment of the invention the casing may be grasped by thumb and fingers upon the end walls, which may conveniently be recessed for this purpose, the palm of the hand extending over the Ilength of the rear wall. With rotor means and interior surfaces operating as a cross flow blower and the inlet in the top wall, as is preferred in this embodiment, it will be seen that the users hand cannot close the air flow openings; the motor will normally represent the main concentration of weight, and lying near the rear wall, will be comfortably within the supporting hand.
In another preferred embodiment the casing is adapted to be grasped by the hand embracing the rear wall, lingers and thumb resting on top and bottom walls respectively fice of the casing. In this embodiment the casing can be made longer: if the rotor means cooperates with interior surfaces to operate as a cross flow blower, as is preferred though not necessary, the inlet may be formed over a relatively large area of the top wall and suitably guarded to prevent sufficient of this area from being obturated by the users hand as to interfere with performance. However, end wall inlets are also contemplated, particularly if the rotor means comprise a pair of centrifugal rotors. Once again, in this preferred embodiment the weight of the appliance, largely represented by the motor, lies under the users hand, and the air flow is directed by the outlet duct for convenient application to the hair.
Preferably the motor is a commutator motor, which can be run fast and thereby enable the rotor to be smaller for a given air flow, with acorrespondingly more compact and readily grasped casing. The motor may conveniently be of low voltage (say 10 volts), part of the heater means being used as a voltage dropper for the motor.
The invention in a further aspect provides a mixing nozzle for use on the outlet of a hair dryer, so that flow through the outlet induces mixing of ambient air with heated air by the injector effect of the latter.
The terms top, bottom, end and rear are used herein solely for convenience of description and do not imply any particular orientation of the hair dryer in space, or any particular mode of use.
Two embodiments of the invention will now be described by way of example with reference to the accompanying diagrammatic drawings, in which:
FIGURE 1 is transverse section of a first form of hair dryer casing of which is adapted to be gripped with fingers and thumb on top and bottom walls;
FIGURE 2 is a top plan View of the FIGURE l hair dryer with parts broken away to show the interior;
FIGURE 3 is a sectional View of a second form of hair dryer the casing of which is adapted to be gripped around the end walls;
FIGURES 4 and 5 are transverse sections of the FIG- URE 3 hair dryer taken on the lines V-V and VI-Vl i respectively of FIGURE 3.
FIGURE 6 shows in section a nozzle unit for use with hair dryers such as illustrated in other figures, one such hair dryer being shown in outline in association with the nozzle.
Referring to the drawings, the hair dryer shown in FIGURES 1 and 2 comprises a housing designated generally 1 having a more or less rectangular shape in plan and looking in vertical section like the section of a truncated pear. The housing has a top wall 2, a bottom wall 3 and end walls 4, 5 and is formed in two interlocking unitary moulded parts, an upper and a lower part, indicated generally at 6, 7 respectively. The top and bottom housing walls 2, 3 curve round to merge with one another and together define an approximately semi-cylindrical rear wall portion 8 over the length of one short side of the rectangle. Within the housing and adjacent the middle of this wall portion is located a small electric motor of low-Voltage commutator type indicated simply as a box and designated 9. The shaft 10 of the motor 9 extends parallel to the wall portion 8 and carries in overhung fashion two similar rotor portions 11, 12, one extending between the motor and one end wall 4 and the other between the motor and the other end wall 5. Each rotor portion 11, 12 comprises a series of curved blades 13 extending from an end support disc 14 mounted on the shaft 10, the blades running parallel to the shaft axis and being arranged in a ring thereabout to define an unobstructed interior space. The blades 13 are concave facing in the direction of rotation indicated by the arrow 15 with their outer edges leading.
The lower housing part 7 includes a partition wall 16 extending between the end walls 4, and from lines 17 adjacent the rotors to the opposite side of the housing 1 where, with the bottom wall 3 and end walls, 4, 5 it defines a slot-like outlet 18. Ove1- its whole extent the partition wall 16 runs approximately parallel to the bottom wall 3: the partition wall 16 and bottom wall together define a flat duct 19 for which the bottom surface of wall 16 forms an upper guide surface and which duct leads from the rotors to the outlet 18, which duct further is convergent due to the rounding-in of the end walls 4, 5 where they approach the outlet, as shown at 20. The partition wall 16 also defines with the top housing wall 2 an entry region 21: air enters the region 21 through a series of slits 21a formed in the top wall 2 in the region thereof near the outlet 18, and flows towards the rotor portions 11, 12. A guide wall 22 extends upwards from the partition wall 16 over the whole length of each rotor portion 11, 12. Each guide wall 22 forms with the corresponding rotor a gap 23 converging with the rotor portion in the direction kof rotation as shown by arrow 15. Each guide wall 22 is rounded into the partition wall at the corresponding line 17 and makes an angle of about 90 therewith. Both the wall portion 8 and the guide walls 22 are well spaced from the rotor portions 11, 12 at their lines of nearest approach.
On rotation of the rotor portions 11, 12 by the motor 9 a Vortex of approximately Rankins type forms in each rotor portion. The core of the vortex is indicated at V and is a whirling body of air with no translational movement as a whole. Flow through each rotor by reason of the vortex takes place approximately along the lines indicated at F, MF, the line MF showing the path of faster stream tubes: in passing through the rotor the air is turned through an angle approaching 180. The air ow leaves through the outlet 18.
The housing parts 6, 7 are rigidifed by ribs 25, 26 formed respectively on the underside of the top wall 2 between the slits 21a and upper side of the partition wall 16. A series of vanes 27 extend between the partition wall 16 and the bottom housing wall 3, at the outlet 18: these vanes cause little obstruction to air flow but rigidify the lower housing part 7 and prevent a users fingers from getting into the outlet 18.
An electric heater 28 extends across the outlet duct I9, and comprises a resistor wire 29 wound about a plate-like insulating support 30 mounted between the end walls 4, 5. An overload cut-out 31 is provided to opencircuit the heater 28 in the event of overheating.
A finger rest 32 is provided above the upper casing wall 2, so that the casing 1 can readily begrasped in the users hand with his palm around the rear wall portion 8, and fingers and thumb respectively over the top and bottom walls 2, 3: the fingers are prevented from blocking the inlet slits 21a.
Part of the resistor wire 29 acts as a voltage dropper for the motor 9.
The hair dryer of FIGURES 1 and 2 can be modified by making the casing 1 more or less rectangular in elevation instead of pear-shaped to increase the volume of the entry region (designated 21 in FIGURE 2) and to provide for slits in the end walls 4, 5 and in a wall above the outlet which slits communicate with the entry region and lead air thereto: because ofv these slits there is no need for apertures in the top casing wall 2 as shown at 21a in FIGURES 1 and 2 and therefore no danger that such apertures might be blocked by a users hand.
The hair dryer of FIGURES 3 to 5 has a casing 5t) which in vertical section through the rotor axis (as seen in FIGURE 3) has an approximately rectangular outline, but with end walls 51, 52 which are slightly concave and top and bottom walls 53, 54 which are convex; the endwise dimension is less than that of the hair dryer of FIGURES 1 and 2 so that the casing can readily be grasped in the hand with lingers and thumb located on the concave end walls, and the palm of the hand extending along a rounded rear wall 55 rounding into the top and bottom walls. The casing 50 is divided into two chambers 56, 57 by a vertical partition wall 58 transverse to the rotor axis. One chamber 59 contains a cylindrical bladed rotor 6i) similar to those of FIGURES l and 2 but shorter in length and larger in diameter and provides the inlet region 61 and outlet duct 62 separated by a partition wall 63 which corresponds somewhat to the partition wall 16 of FIGURE 2. A largearea inlet 64 is provided in the top wall 53 leading to the inlet region 61: ow guide vanes 65 extend across the inlet 64 and prevent a finger from entering it. Vanes 66 extend across the outlet 67 and prevent a finger from entering the outlet duct 62. Vertical partition wall 58 and the end wall 51 are recessed on their faces defining the chamber 56 to accommodate end support discs 69 of the rotor 60. The chamber 57 contains a motor 70, and the rotor 60 is overhung-mounted on the armature thereof. Apertures 71, 72 in the vertical partition wall 58 permit communication respectively between the top and bottom of the chamber 57 and the entry region 61 and outlet duct 62 of the chamber 56, whereby in operation to induce a stream of cooling air past the motor.
The partition wall 63 presents to the rotor 60 at its nearest approach thereto a guide surface 73 which is spaced relatively far from the rotor: the purpose of this spacing is to permit electric heater wires 75 to extend across both the outlet duct 62 and the inlet region 61. The wires 75 are suspended between hooks 76 secured to a vane 65 above the rotor 60, hooks 77 fixed to the bottom wall 54 below the rotor, and hooks 78 supported on the partition wall 63 through springs 79 which apply tension to the wires to keep them taut.
Certain similarities between the hair dryer of FIG- URES 1 and 2 and that of FIGURES 3 to 5, will be apparent especially from comparison of FIGURES 1 and 4. However, the two hair dryers are designed to fit the hand in different ways, and for this reason the dimensioning of their respective parts is very different.
In operation of the hair dryer of FIGURES 3 to 5, the rotor 60 co-operates with the guide surface 73 and interior of the rear wall 55 to induce a flow of air through the inlet 64 into the entry region 61`and thence twice through the path of the rotating blades of the rotor 60, and through the outlet duct 62 and out of the outlet 67. The flow pattern is generally similar to that illustrated in FIGURE 2, and will not require further description.
FIGURE 6 shows a nozzle unit 115 which can be adapted for use with either of the hair dryers according to the invention: by way of example, the appliance of FIGURES 1 and 2 is shown in outline in FIGURE 6, while the unit is shown attached to the hair dryer in FIGURE 2. The nozzle unit 115 comprises upper and lower profiled deector elements 116, 117 interconnected by end members 118 and is arranged for mounting on the casing of the hair dryer about the outlet 45 therein so that the deector elements are spaced from the casing. Air is discharged from the outlet between these elements and has an injector action on ambient air; by this means a proportion of the latter is induced to flow over the casing 41 and between the deector elements as shown by the arrows 119 and to mix with the air from the outlet. The air leaving the outlet 45 will normally be hot, and the admixture of ambient air in the nozzle unit 115 reduces its temperature somewhat.
The nozzle unit 115 is particularly useful where the motor is of low-voltage type andseries-connected with the heater unit, so that the heater unit cannot be switched olf. The nozzle unit can be made detachable, or can bel made to pivot or otherwise move between an operative position (as illustrated) and an inoperative position. Various different shapes of the deector elements are contemplated.
1. A hair dryer comprising a casing having a top wall having a finger rest portion thereon, a bottom wall, a curved rear wall merging into the top and bottom walls and closed end walls joining the top and bottom walls, said curved rear wall of the size adapted to rest between the thumb and forenger when the casing is grasped in the hand, the casing having an inlet over an area of the top wall, and an outlet between the end walls opposite the rear wall; motor driven bladed cylindrical rotor means adjacent the rear wall wit-h the rotor means opposite the outlet; a partition positioned between the top and bottom walls dening with the interior surface of the casing bottom wall an outlet duct leading from the rotor means to the outlet; a guide surface on the end of the partition adjacent said rotor; and electric heater means extending completely across the path of air ow passing from the inlet to the outlet; the rotor means in operation cooperating with the guide surface to induce a ow of air into the inlet, through the outlet duct and out of the outlet.
2. A hair dryer as claimed in claim 1, comprising vanes extending across the outlet and preventing entry of a users finger therein.
3. A hair dryer as claimed in claim 1, comprising vanes extending across the inlet and preventing entry of a users nger therein, the vanes extending parallel to the axis of the rotor means and being angled to guide ilow thereinto the rotor means.
4. A hair dryer as claimed in claim 1, having a dividing wall extending parallel to the end walls defining two compartments, one compartment containing the motor and the other compartment containing a single rotor providing said rotor means and having one end mounted on the motor shaft, the inlet and outlet being aligned with and extending over the length of said rotor.
5. A hair dryer as claimed in claim 4, wherein the rotor is overhung-mounted on the motor shaft.
6. A hair dryer as claimed in claim 1, wherein the heater means includes resistance wires extending across both inlet and outlet sides of the rotor means.
7. A hair dryer as claimed in claim 1, wherein said end walls are dished to locate a users fingers and thumb respectively.
8. A hair dryer as claimed in claim 1, wherein the casing is formed in two parts mated together along a plane between top and bottom walls.
9. A hair dryer as claimed in claim 8, wherein the motor and rotors form a sub-unit and one of said casing parts is formed to receive and locate the motor.
10. A hair dryer according to claim 1 having in addition a mixing nozzle extending over said outlet and defining with the casing about the outlet at least one slit extending lengthwise thereof whereby flow through the outlet induces a flow of ambient air through said slit by injector action, the ambient air mixing with the air stream passing through said outlet.
11. A hair dryer comprising a casing having a top wall, a bottom wall, a curved rear wall merging into the top and bottom walls of a size adapted to rest between the thumb and forenger when the casing is grasped in the hand, and end walls joining the top and bottom walls;
bladed cylindrical rotor means mounted adjacent the rear wall; an inlet in the top wall, and an outlet 4having a rectangular slot-like form extending between the end 6 between the end walls, and said outlet being the same length as said rotor means; a partition positioned between the top and bottom walls and defining with the interior surface of the casing bottom wall an outlet duct leading from the rotor means to the outlet; and electric heater means in said outlet duct extending across the Width thereof; the rotor means being effective upon actuation of the motor to induce a flow or air into the inlet means through the outlet duct past the heater means and out of the outlet.
12. A hair dryer as claimed in claim 11 wherein the rotor means comprise a pair of rotors overhung mounted onthe ends of the motor drive shaft.
13. A hair dryer as claimed in claim 11 wherein the casing, seen in cross-section perpendicular to the axis of the rotor means, Jhas the cross-section of a truncated pear.
14. A hair dryer comprising a casing having a top wall, a bottom wall, a curved rear wall merging into the top and bottom wall of a size adapted to rest between the thumb and forenger when grasped in the hand, end walls, an inlet, and an outlet having a rectangular slot like form extending between said end walls; motor driven bladed rotor means inducing in operation a flow of air in the rotor and out of the outlet; electric heating means in the casing and extending completely across the path of air flow, and a mixing nozzle in rectangular form as seen in elevation facing the outlet mounted on the casing and terminating at a throat downstream of but closely adjacent to said outlet, the nozzle extending over said outlet in alignment therewith and defining with the casing about the outlet at least one slit extending lengthwise thereof whereby flow through the outlet induces a flow of ambient air through said slit by ejector action such that the ambient air mixes in said throat with air stream through the outlet.
15. A hair dryer comprising a casing having a top wall, a bottom wall, a curved rear wall merging into the top and bottom walls, end walls joining the top and bottom walls, said curved rear wall of the size adapted to rest between the thumb and forenger when the casing is grasped in the hand, an air inlet in the top wall, and a slot-1ike outlet extending between the end walls opposite the rear wall; motor driven bladed cylindrical rotor means adjacent the curved rear wall with the rotor means opposite the outlet; an outlet duct leading from the rotor means to the outlet; a guide surface exterior of the rotor and adjacent thereto; a commutator motor in said casing adjacent said curved rear wall for driving said rotor; and electric heater means extending completely across the path of air flow passing from the inlet to the outlet; the rotor means in operation cooperating with the guide surface to induce a How of air into the inlet, through the outlet duct and out the outlet.
References Cited by the Examiner UNITED STATES PATENTS 1,594,906 8/1926 Gross 219-364 1,821,525 9/1931 Nielsen 219-370 1,920,952 8/1933 Anderson 230-125 2,306,727 12/ 1942 Hill 230-45 2,942,773 6/ 1960 Eck 230-125 FOREIGN PATENTS 559,024 1/1958 Belgium. 666,072 2/ 1952 Great Britain.
ANTHONY BARTIS, Primary Examiner.
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,284,611 Dated NOI/81111361 8, 1966 Nikolaus Laing Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column l in the head ing after "claims prior ity, application Germany April l7 1959 L 33210 insert and application Germany, Apr. l5, 1959, L 32977 Signed and sealed this 20th day of March 1973.
EDWARD M.PLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents