US3832789A

US3832789A - Nestable hair dryer with tensioned positioning

Info

Publication number: US3832789A
Application number: US00317539A
Authority: US
Inventors: N Bartram
Original assignee: Schick Inc
Current assignee: Conair Corp; Schick Inc
Priority date: 1972-12-22
Filing date: 1972-12-22
Publication date: 1974-09-03
Anticipated expiration: 1991-09-03
Also published as: GB1443761A; CA1012757A; JPS5310503B2; NL7315749A; JPS4996853A; BR7310030D0; IT999641B; DE2352556A1; BE808400A; NO135733B; NO135733C; AU6062973A; FR2211193A2; FR2211193B2

Abstract

A nestable portable hair dryer which includes a base, a head supporting assembly, and a dryer head assembly, in which the base and dryer head assembly are pivotally mounted at opposite ends of the head supporting assembly in a ''''hinged Z'''' configuration. The dryer head assembly includes a generally annular air distribution plenum therein for receiving drying air and directing it radially inwardly, and a cover which is movably mounted with respect to the annular plenum. A squirrel cage blower is contained in an impeller housing disposed at the lower end of the head supporting assembly. It directs air upwardly through the head mounting assembly through a conduit in which air heating means are positioned, to an upper portion of the head mounting assembly which terminates in a horizontally disposed tube having means engagable with portions of the plenum to provide for passage of air through the head support and into the interior of the plenum while also permitting adjustment of the position of the head assembly with respect to the head mounting assembly. The dryer includes a head counter-balancing feature comprising a wound coil spring assembly in which the coil is wound around a post which is fixed with respect to the head support element. The coiled spring is arranged to permit the ''''free'''' end which is fixed to the other dryer element to be pulled to many positions, to provide constant tension to keep the dryer hood in any position selected by the user. This tensioning feature provides substantially constant tension to keep the dryer hood in any position selected by the user, and is particularly advantageous in permitting reliable noiseless adjustment of the head between an extreme elevated position and a normal elevated operating position.

Description

United States Patent Bartram m 3,832,789 Sept. 3, 1974 1 NESTABLE IIAIR DRYER wITiI TENSIONED POSITIONING 75 Inventor: Nial c. Bartram, Wilmington, Del.

[73] Assignees Schick Incorporated, Lancaster, Pa.

22 Filed: Dec. 22, 1972 [21] Appl. No.: 317,539

[52] US. Cl 34/99, 34/239, 248/280,

- 248/292 [51] Int. Cl A45d 20/24 [58] Field of Search 34/96-101,

Primary ExaminerJohn .J. Camby Assistant Examinerl-lenry C. Yuen A 57 1 ABSTRACT A nestable portable hair dryer which includes a base, a head supporting assembly, and a dryer head'assembly, in which the base and dryer head assembly are pivotally mounted at opposite ends of the head supporting assembly in a hinged Z configuration. The dryer head assembly includes a generally annular air distribution plenum therein for receiving drying air and directing it radially inwardly, and a cover which is movably mounted with respect to the annular plenum. A squirrel cage blower is contained in an impeller housing disposed at the lower end of the head supporting assembly. It directs air upwardly through the head mounting assembly through a conduit in which air heating means are positioned, to an upper portion of the head mounting assembly which terminates in a horizontally disposed tube having means engagable with portions of the plenum to provide for passage of air through the head support and into the interior of the plenum while also permitting adjustment of the position of the head assembly with respect to the head mounting assembly. The dryer includes a head counter-balancing feature comprisinga wound coil spring assembly in which the coil is-wound around a post which is fixed .with respect to the head support element. The coiled spring is arranged to permit the free'endwhich is fixedto the other dryer element to be pulled to many positions, to provide constant'tension to keep the dryer hood in any position selected by the user. This tensioning feature provides substantially constant tension to keep the dryer hood in any position selected by the user, and is particularly advantageousin permitting reliable noiseless adjustment of the head between an extreme elevated position and a normal elevated operating position.

20 Claims, 11 Drawing Figures PATENIEDsm 1974 ME! 1 0F 3 mm .m

\ Ilih cu m memansm m4 3,882,789

MEI 20$ 3.

This invention can be regarded as an improvement of the invention described and claimed in a prior copending US. patent application, Ser. No. 229,763, filed Feb. 28, 1972, now US. Pat. No. 3,775,861, by Robert S. Waters, Edward J. Doyle, Meyric K. Rogers and Nial C. Bartram, which prior co-pe'nding application is owned by acommon assignee with the present invention, and in which said Nial C. Bartram is the inventor hereof.

Thus, the present invention relates generally to hair dryers, and more particularly, to those hair dryers having a rigid dryer head assembly which includes portions adapted to surround at least apart of the head of the user, and which are occasionally referred to in the trade as hard hat hair dryers. Such hard hat dryers are'distinguishable from other types of dryers, such as dryers having flexible bags or caps which surround the.

head of the user and which include a flexible hose-like conduit extending between the cap and a blower for heated air and from' dryer's of the hand-held type wherein no means is provided for surrounding-any substantial portion of the head of the user.

Although hair dryers of both the hand-heldtype and the flexible cap type have proven acceptable to the trade, it is well known that the hair dryers having rigid drying heads or hood units are superior in use, principally because th eyare silificiently rigid to contain fixed physical structure which serves to directthe air to desired portions of the hair of the user in accordance with a predetermined pattern. Recently, hair dryers of the rigid head or hard-hat type have become relatively common home appliances, and have achieved a certain currency because they have been able to be manufactured and sold at reasonable prices. Such dryers are generally designed so as to overcome the drawbacks associated with commercial or heavy duty hair dryers, namely, substantial mass, lack of portability, and the requirement of using substantial amounts of electrical current.

In the aforesaid co-pending application, a hardhat dryer is disclosed having a general configuration of a nestable, hinged 2" configuration in which the dryer the respective rings undergo rotation, one relative to the other. The mating engagement under the spring bias prevents the relative rotation of the head assembly and the head mounting assembly from the position selected by the user. I

Thus, the head mounting assembly can be adjustably positioned for use, or can be completely lowered toa nested or storage configuration, as desired, while'still being self-supporting and adjustable'while in the open, in-use configuration. The adjustment was incremental, however, in the sense that it could be held only at those many positions in which ratchet teeth are engaged. Also, the adjustment was accompanied by rather loud clicking as the teeth rode in and out of mating alignment. i

It is an object of the present invention to provide a portable hair dryer of the hinged Z configuration having silent pivot means for adjusting the head asembly and for positioning the head assembly in storage configuration, as desired, while still providing means for the head assembly to be self-supporting and infinitely adjustable in the in-use configuration.

It is another-object of the present invention to provide biased pivoting means whereby substantially constant tension can be maintained with respect to the head-assembly while the head assembly is. pivoted through a variety of configurations ranging from the extreme open configuration to the completely closed nested configuration. v

It is a further objectof the present invention to provide positioning and pivot means for adjustably positioning a dryer assembly of the hinged Z configuration, which pivot means does not require the use of 'matingratchet-teeth, and which provides substantially infinite adjustment rather than the incremental adjustment which is achieved when ratchet teeth are used.

comprised a base and a head supporting element which pivotally articulated to nest within the head assembly for storage, and in which the head assembly, head mounting assembly and base are articulated for opening into a Z operating configuration. In the dryer disclosed in the aforesaid prior co-pending application was included a novel arrangement of parts providing improved ease of opening and closing and permitting, ready adjustment between a variety of positions used. In a preferred embodiment of the prior aforementioned co-pending application, the pivot assembly means for nested storage configuration.

It is a further object of the present invention to provide a biased pivot means which obviate the necessity of a clicking vnoise while the pivotal elements are moved with respect to one another, and which provides a smooth, vibration-free movement during adjustment.

These and other objects which will be apparant hereinafter are all achieved in accordance with the present invention which is described herein in connection with a preferred embodiment and with the aid of the accompanying drawings in which:

I FIG. 1 is a perspective view showing a hinged Z dryer in operating configuration.

FIG. 2 is an enlarged cut-away view of the portion of the'dryer of FIG. 1 bridgingthe head support element and the head plenum when these elements are in the FIG. 3 is a fragmentary sectional view taken approximately alongth'e line 3-3 of FIG.- 2.- v

FIG. 4 is a view taken along the line 3-3 when the elements are in an open or in-use. configuration as shown in FIG. 1.

FIG. 5 is a view taken along the line 5-5 of FIG. 2.

construction.

FIG. 7 is a side view of a spring mounting bracket.

FIG. 8 is a top view of the bracket shown in FIG. 7.

out appearance.

FIG. 9 is a plan view of the coiled spring in its lay- FIG. 10 is a side view of the coiled spring FIG. 9. 7

FIG. l1 is a side view of the tightly coiled spring in its at-rest configuration.

The manner in which the objects set forth above and other inherent objects and advantages of the present invention are carried into practice will become more clearly apparant when reference is made to the accompanying detailed description of the preferred embodiment of the invention set forth by way of example and shown in the accompanying drawings, in which like reference' numbers indicate corresponding parts throughout. Also, in the discussion of the pivoting motion of elements, it will be appreciated that, unless otherwise indcated, the pivoting motion is relative, and, in fact, one element moving with respect to another, may, as a practical matter, be the stationary element.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION Although it will be understood that the invention may be embodied in a number of different forms, a description thereof will be made with respect to an embodiment wherein a head assembly, which includes a movable mounted cover surrounding a generally annular plenum and an improved air-flow control system is mounted for pivotal movement about a portion of the shown in plenum disposed atop the head mounting unit, thelower portion of which also includes an impeller and mounting unit pivoting relative to the base as well as to the head assembly to permit both the base and the head mounting unit to be received within the head assembly and retained therein.

In accordance with the illustrated preferred embodiment of the present invention, a wound or coiled spring which is in a tightly wound configuration in its at-rest condition is positioned with the coil portion thereof about a post which is fixed to one of the dryers pivoting elements, e.g. to the head mounting assembly, and the outwardly extending or freelend of the spring is fixed with respect to the other element, e;g. to the head assembly, to be pulled or elongated asthe pivoting elements are pivoted with respect to one another'in one direction, and to be retracted or re-coiled as the pivoting elements are pivotedin the other direction. The spring attachments must be made in such a manner as to urge the pivoting elements towards theopen or operating configuration. Hence, the post 72can be fixed with respect to either pivoting

element

64, 22,,providing free end 75 of spring 72 is fixedwith respect to the other pivoting

element

22, 64, and the direction in which-free end 75 extends causes the pull of the spring to counterbalancethe gravity-induced tendency for the elements to pivot' with respect 'to each other. Post 72 need not be fixed to a bushing 70, but, equivaherein by referencethereto;

lent post attached directly to plenum 64 and extending into head assembly 22 could be used providing alignment means serving the similar function to bushing are provided. 'In the illustrated embodiment, the free end is pulled farthest, that is, the coil is unwound to the greatest extent when the elements are provided to the nested configuration; The spring is wound to the greatest extent around the post when the unit is pivoted to the operating configuration.

The nature of the spring and the cooperating relationship of the various co-ac'ting' element provides constant tension to keep the dryer hood in any position selected by the user, against the force of gravity and in spite of any vibration normally encountered in the dryer. v

' Referring now to the drawings in greater detailpFIG. 1 shows a dryer assembly generally designated by the numeral 20 having a head assembly 22 pivotally mounted atop a head mounting assembly 24, the lower portion of which forms an impeller housing 26 received within a base unit 28. The head assembly 22 includes an uppercover or she'll portion 30, and the exterior wall portion-32 of a somewhat-elongated, generally annular, drying air distribution plenum 34 having a plurality of radially'inwardly directed openings 36 therein. In

this regard, it should be noted that plenum '34 can be considered to'be generally annular even though the portion of plenum 34 within head assembly 22has the general shape of letter C,- and the loopof the annulus is closed by horizontally disposed inner plenum 64 at the top of head support assembly 24. The base assembly 28 includes a pair of lugs 3838 having a louvered annular inlet opening 40 for fresh air, and'each having a tray assembly 42 associated therewith for. receiving pins, curlers, or the like. The front wall 44 of the base assembly 28 includes-an edge portion 46 of reduced height, permitting the neck portion 48 of the head mounting assembly '24 to be placed in, various positions with respect thereto. I I

As indicated by the double-ended arrow identified by the letter A in FIG. 1, the head assembly 22 is pivotal with respect to headmounting assembly 24, and, as indicated by the double ended arrow identified by the letter B, the headmounting assembly 24 is pivotally movable with respect to base 28. The .pivoting and holding means whereby head support assembly 24 is pivoted with respect to base element 28 and held in a desired position is conventional and can be, for example, as shown in the aforesaid patent application, the discussion and illustration of which is incorporated Thus, the dryer unit 20 may be collapsed for storage by pivoting the cover or shell 30 to lower the cover 30 to a position wherein the loweredge 52-closely overlies an inclined upper locating edge 54 formed on .wall 32. Head mounting assembly 24 pivots into the interior of head assembly 22,. and head mounting assembly 24 is also pivoted withrespect to base 28 to reside between legs 38-38so that the bottom 55 of base element 42 is even with the mouth 56 of plenum 34. Handle 62 (see FIG. 3 remains exposed for gripping and carrying the dryer in the collapsed or storage configuratiomBy reason of the design of the principal elements of the dryer 20,the profile presented by the unit 20 in the retracted or collapsed storage configuration thereof is much lower than the profile able to be achieved with dryers of other designs. Nonetheless, the dryer is highly effective by reason of the construction of the plenum 34 and the air flow control assembly.

The details of the pivot assembly in accordance with the preferred embodiment of the present invention are illustrated in FIG. 2. As indicated above, the crosssectional view of FIG. 2 is taken through a portion of the dryer which bridges the head support element 24 and the head assembly 22, and, more particularly, plenum 34. The view shown in FIG. 2 shows portions of these elements in the relative positions encountered when the elements are in the nested or storage configuration. The illustrated bridging pivotassembly generally indicated by the numeral 62 involves the righthand portion of the annular inner plenum 64 at the upper end of head mounting assembly 24, and the right-hand portion 66 of the annular duct or plenum 34 of the head assembly 22 as viewed in FIG. 1. Inner plenum 64 is of the nature of a horizontally disposed tube. It is apparent from a consideration of FIG. 2 that the annular inner plenum 64 and annular duct 66 concentrically butt at axial ends thereof to provide a continuous conduit 67 for the passage of air therethrough. Bridging between annular inner plenum 64 and annular duct 66'is a strong, rigid bushing 70 of complex shape having spring mounting'spool 72 secured thereto. A wound coil spring 74 is positioned around spool 72 and is retained thereon by keeper flange 73. Bushing 70 is fixed with respect to inner plenum 64.

As seen in FIG. 3, bushing 70 includes axially extending resilient fingers 787'8 having radially outwardly extending detents 808 0 near the ends thereof. Detents 80 are adapted to engage radially inwardly extending'flange 82 in inner plenum 64, securing and fixing bushing 70 axially'with respect to plenum 64. At the axially facing end of bushing 70 which is in the axially opposite direction from fingers 7878, a radially outwardly extending flange 84 engages an axially facing radially inwardly extending annular flange 86 which is integral with annular duct 66. It is noted that the radially outwardly extending flange 84 in bushing 70 has a wider radius than the opening formed by radially inwardly extending flange 86. The annular flange 86 through which bushing 70 closely passes and which is engaged by radially outwardly extending flange 84 is of integral molded construction and is integral with inside wall 87 and bottom 88. Integral outer wall 32 meets bottom 88 along a parting line 89. An outer wall 32 is formed in a separate molding operation, preferablyintegral with the top portion of conduit 34, and is fitted over the inner wall portion along line 89. FIG. 2 shows outer wall 32 extending rearwardly around the annular duct 66 which is'integral with the inner wall 87 and bottom 88. The parting line 89 is about parallel to the outer wall in the cross-section shown in FIG. 2.

' In FIG. 3, the bridging portion 62 is shownain a cutaway view, and the relationship between FIG. 3 and FIG. 2 can be appreciatedfrom a consideration that FIg. 2 is a cross-sectional view taken approximately along the line 22 in FIG. 3. a It willbe appreciated from a consideration of FIG 3 that a rigid spring mounting bracket 90 is secured at one. end 92 thereof to a bottom wall 88 of head assembly 22 by rivets 94 or other suitable fastening means.

The other end 96 is shaped to provide a keeper clip 98 for mating engagement with an opening 100 as shown in detail in FIGS. 7 and 8, and spring 74 shown in detail in FIGS. 9, l0 and 11. The illustration of spring 74 shown in FIGS. 9 and 10 is intended to provide an understanding of the general size and configuration of the metal spring leaf from which coil spring 74 is made. FIG. 11 provides a side view of the spring showing the spring in its tightly wound at rest or relaxed configuration. Thus, it will be appreciated from a consideration of FIG. 11 that in its at rest or relaxed configuration, spring 74 has the general config uration of a tightly wound coil, having a free outer end 75 and having a central opening 101 at the center of a tightly wound coil portion 102. Central opening 101 is sized to receive post 74 therein.

Referring again to FIG. 3, it will be appreciated that coil portion 102 of spring 74 is merely positioned around post 72, and free end 75 of spring 74 is secured to keeper 96 of mounting bracket 90 which, in turn, is secured with respect to head mounting assembly 24. Coil portion 102 of spring 74 is not fastened to spool or post 72, and coil 102 is free to rotate in either direction around post 72.

Spring winding post 72, being an integral part of bushing ,70, is therefore fixed with respect to bushing 70. Bushing also includes a radially outwardly extending keying boss 103 which extends into a locking notch 104 in head mounting assembly 24 as shown in FIG. 6. Thus, spring-winding spool 72 is fixed with re spect to head mounting assembly 24.

To further describe emminently satisfactory relative proportions of the elements in a preferred embodiment of the present inventionjfor a dryer assembly in which the inside diameter of the bushing 70 which defines-the outer limits of the conduit 67 in pivot portion 62 which is approximately 2 7% inches, a double spring 74 which is approximately 8 inches long, and wound to provide a tightly wound coil and treated to have an outside diameter of approximately limb and toprovide a 7 7% pound pull is emminently satisfactory. A preferred material from which spring 74 is made is stainless steel strip having high tensil temper and having more than 250,000 PSI minimum tensil strength. In a preferred embodiment, spring 72 consists'of two

separate layers

107, 108 having a slight arch running their entire length in the elongated direction with the apex of the arch pointing in .the direction which would be radially outwardly when the coil portion 102 is tightly wound. Of course, the arch tends to disappear in that portion 102 which is tightly wound. Layers 107, 108 (see FIG. 9) are secured with respect to each-other adjacent the end thereof such as, for example, by spot welding at points l09l09 (see FIG. 9). When spring 74 is tightly wound, shorter layer is inside adjacent portions of layer 107. v

Referring to FIG. 4, it will be appreciated that the elements shown in FIG. 4 are identical to the elements shown in FIG. 3 except that the head mounting assembly 24 and head assembly 22 havebeen pivoted with respectto each other. Consequently; the spring winding post 72 remains fixed with respect to and shown moved with head mounting assembly 24, and is shown pivoted to a position which is closer to keeper 96 which, in turn, is fixed with respect to head assembly 22. The pivoting of head mounting assembly 24 with respect to head assembly 22 thereby permits spring 74 to coil, or perhaps recoil around post 72.

Since the at-rest or relaxed condition of spring 74 is the tightly coiled configuration, it-will be appreciated that spring 74 resists being pulled to the un-wound configuration shown in FIG. 3 and readily winds itself around spring winding post 72 and urges post 72 towards anchored free end 75. As a practical matter, however,'in the illustrated embodiment, it is the spool or post 72 which is stationary or fixed with respect to the head mounting assembly 24, and it is bracket 90 and particularly end 96 thereof which is urged toward post 72, thus causing head 22 to be urged to the open pivotal position and against the forces of gravity. Thus, in the open configuration of the dryer shown in FIG. 1, most of the spring 74 is tightly wound as shown in FIG. 4, and in the closed position shown in FIG. 3, most of the spring 74 is extended. However, because of the coiled configuration of spring 74, there is constant urging in the open and closed position.

It is noted that in the illustrated preferred embodiment of this invention, bushing 70 is bilaterally symmetrical around the axially extending plane passing through the broken line identified by the letter C" in FIG. 4. This line passes through the center of spring winding post 72 and through the center of key boss 103. By providing a bushing 70 which is bilaterally symmetrical as illustrated, itis possible to use the same identical unit 70 at both sides of the dryer assembly 20 whereby the bridging pivot assembly 70 is a mirror image of the corresponding bridging pivot assembly 62 at the left side. In the preferred embodiment, therefore, both the right and left sides of plenum 64 are provided with pivot assemblies 62 which are mirror images of each other, although a dryer having the pivot counterbalance mechanism vcomprising bushing 70, post 72 and spring 74 on only one side of the inner plenum 64 is useful, providing spring 72 is'selected from among those springs having sufficient pull to counterbalance the forces of gravity on the particular head assembly.

Thus, one pair of spring guides 110-110 which extend axially are positioned on one side of the plane C of symmetry, and a second pair 112112 are positioned on the opposite side of the plane. It is apparent from a consideration of FIG. 3 that the spring keepers 110-1110 engage the radially inner facing side of spring 74 when the spring 74 is in its extended condition corresponding to the nested configuration of dryer 20, and the other keepers ll2112 would appear to have no function whatsoever. Nonetheless, when an identical bushing 70 is .incorporated into the opposite side at the bridging pivot assembly 63, it will be appreciatedthat it will be the keepers 112-112 which engage spring 74 in the mirror image of that shown in FIGS.- 2, 3 and 4, and keepers 110110 which would appear to have no function. 1

' Thus, as post 72 is forced away'from keeper clip 98, when the user lowers-the head assembly, spring 74 and particularly free end 75 extends. However, spring guides 110-110, 112-112 bear against the radially inward face of the extended end 75 of spring 74, keeping spring 74 at a fixed radius from the center, thus keeping the relative direction of the urging at a substantially constant angle, for example, at a right angle, with respect to the pivot radius. While this feature prevents kinking of the spring due to sharp bends at spool 72 by maintaining free end 75, spring 74 along a path having a desired minimum radius, this feature also ensures the characteristic that the urging by the spring will be constant regardless of theangular rotation of the head 22 with respect to the head mounting assembly 24.

It will be appreciated from a consideration of FIGS;

3 and 4 that the spring 74 and spring winding post 72 are positioned within the head assembly 22 adjacent the rear wall 114 and bottom wall 88, and, consequently, the spring 74 and spring winding post 72 have an insignificant effect on the flow of heated air through conduit 67.

The preferred embodiment described in detail herein is for the purpose of illustration of the invention and is not intended to be limiting. The pivot counterbalancing mechanism comprising bushing 70, post 72, spring 74 in the pivot upstanding element 24 and generally horizontal element 22 can be advantageously adapted to other applications.

I claim:

1. In a hair dryer of the type which includes a head assembly having a defined region for receiving a portion of the head of a user and a C-shaped first portion of an air distribution plenum for directing air onto said defined region, said first portion of said air distribution plenum having axially-aligned annular inlet ports at either end thereof for receiving air under pressure; head support assembly including a generally horizontal second portion of said air distribution plenum and a source of air under'pressure, said second portion of said air distribution plenum commuriicating with said air source and having a pair of horizontally-opposed annular outlet ports axially aligned with respective ones of said annular. inlet ports; and i coupling meanscomprising at least one cylindrical bushing extending between adjacent ones of said axially aligned inlet and'outlet ports for bridging the gaps between the inlet ports of said C-shaped first plenum portion and the outlet ports of said second plenum portion to deliver air from said source to said head receiving region, said coupling means establishing a generally horizontally disposed pivot axisbetween said head assembly and said head support assembly coaxial with said inlet and outlet ports;

an improved counter-balancing assembly for said head assembly comprising:

tension means comprising at least one wound coil spring positioned in a plane perpendicular to said pivot axis;

first attachment means for fixing the position of one end of said spring relative to said head assembly;

second attachment means for fixing. the position of the other end 'of said spring relative to said head support assembly; and 1 alignment means for maintaining at least a portion of said wound coil spring positioned in an arcuate path having a desired constant minimum radius with respect to said pivot axis wherebysaid spring offers minimal interference to the passage of air through said bushing and whereby the forces gen; erated by said spring at each end thereof are maintained substantially constant and in directions which are at respective substantially constant angles' to the respective radii of the points of attachment of said spring within a predetermined range of relative angular positions between said head assembly and said head support assembly to counterbalance said head assembly against the forces of gravity.

2. A hair dryer as defined in claim 1 wherein said constant angle is a substantially right angle with respect to the radius at the innermost of said attachment means.

3. The hair dryer of claim 1 in which said alignment means include spring-guide means fixed with respect to one of said portions of said airdistribution plenum and extending axially into the other portion of said plenum along a path radially inwardly of said constant radius portion of said wound coil spring for engaging a radially inwardly facing portion of said spring to confine said portion of said spring in an arcuate region having said desired constant inner radius with respect to said pivot axis.

4. The hair dryer defined in claim 1 wherein individual cylindrical bushings are provided between adjacent ones of said inlet and outlet ports and said tension means comprise a pair of wound coil springs disposed adjacent to respective ones of said bushings.

5. The hair dryer defined in claim 1 wherein said bushing extends between said first portion and said second portion of said air distribution plenum, and wherein said bushing has keying means cooperating with one of said plenum portions to fix said bushing with respect to said portion, and wherein said bushing also includes a portion thereof positioned in the other of said plenum portions providing attachment means for one end of said wound coil spring, and wherein said bushing includes rigid guide'means positioned radially inwardly of said spring to engage the radially inward extreme of said spring to maintain at least a portion of the portion of said spring extending between said first and second attachment means in an arcuate path having a minimum desired'radius with respect to the axis of pivot of said head assembly and said head support assembly.

6. In a hair dryer of the type which includes a head assembly having a defined region for receiving a portion of the head of a user and a' C-shaped first portion of an air distribution plenum for directing air onto said defined region, said first portion of said air distribution plenum having axially-aligned annular inlet ports at either end thereof for receiving air under pressure;

head support assembly including a generally horizontal second portion of said air distribution plenum and a source of air under pressure, said second portion of said air distribution plenum communicating with said air source and having a pair of horizontally-opposed annular outlet ports axially aligned withrespective ones of said annular inlet ports; and 1 j coupling means comprising at least one cylindrical bushing extending between adjacent ones of said axially-aligned inlet and outlet ports for bridging ,the gaps'between the inlet ports of said C-shaped first plenum portion and the outlet ports of said second plenum portion to deliver air from said source to said head receiving region, said coupling means establishing a generally horizontally disposed pivot axis between said head assembly and said head support assembly coaxial with said inlet and outlet ports;-v a an improved counter-balancing assembly for said head assembly comprising: i

tension means comprising an elongated strip of spring metal having a tightly wound coil portion with a central opening and a free end portion extending from the periphery of said coil portion, said spring being positioned in a plane perpendicular to said pivot axis adjacent said cylindrical bushing;

first attachment means comprising a spring winding post extending through said central opening for fixing the position of said coil portion of said spring relative to one portion of said air distribution plenum,

second attachment means for fixing the position of said free end portion of said spring relative to the other portion of said air distribution plenum; and

alignment means for maintaining said free end portion of said spring positioned in an arcuate path having a desired constant minimum radius with respect to said pivot axis greater than the radius of said cylindrical bushing whereby said spring offers minimal interference to the passage of air through said bushing and whereby the forces generated by said spring at each end thereof are maintained substantially constant and in directions which are at respective substantially constant angles to the respective radii of the points of attachment of said spring within a predetermined range of relative angular positions between said head assembly and said head support assembly to counter-balance said head assembly against the forces of gravity.

7. A hair dryer as defined in claim 6 which further includes spring-guide means comprising at least one axially extending element which is fixed with respect to said one of said portions of said air distribution plenum, and which extends into said other of said portions to a position radially inwardly of said free end portion of said spring, said spring guide means urging said spring into said arcuate path whereby said free end portion has a constant minimum radius 'with respect to the of rotation of said head assembly and said head support assembly. 7 j

8. A hair dryer as defined in claim 6 wherein said spring winding post and spring are positioned in the region which is adjacent a rear wall and bottom wall of said first portion of said air distribution plenum.

9. A hair dryer as defined in claim 6 wherein individual cylindrical bushings are provided between adjacent ones of said inlet and outlet ports, wherein said tension means comprise a pair of wound coil strips adjacent each or said bushings, and wherein said attachment means are provided for each of said coil strips.

10. A hair dryer as defined in claim 6. which further includes key means for securing said bushing to one of said plenum portions, and wherein said bushing includes said spring winding post integral therewith, and wherein said bushing also includes axially. extending springguide means extending to a position radially inwardly of said free end of said spring for urging the free end portion of said spring into said arcuate path.

11. A hair dryer comprising, in combination:

, a head assembly having a defined region for receiving a portion of the head of a user and a C-shaped first portion of an air distribution plenum for directing air onto said defined region, said first portion of said air distribution plenum having axiallyaligned annular inlet ports at eitherend thereof for'receiving air under pressure;

a head support assembly including a generally horizontal second portion of said air distribution plenum and a source of air under pressure, said second portion of said air distribution plenum communicating withsaid air source and having a pair of horizontally-opposed annular outlet ports axially aligned with respective ones of said annular intake ports;

' coupling means comprising at least one cylindrical bushing extendingbetween adjacent ones of said axially-aligned inlet and outlet ports for bridging the gaps between the inlet ports of said C-shaped first plenum portion and the outlet ports of said second plenum portion to deliver air from said source to said head receiving region, said coupling means establishing a generally horizontally disposed pivot axis between said head assembly and said head support assembly coaxial with said inlet and outlet ports; I

tension means including a'wound coil spring having, in its relaxed position, a tightly wound coil portion having a center opening, and a free end portion extending therefrom, said spring being positioned in a plane perpendicular to said pivot axis;

first attachment means including a spring winding post extending through said center opening for fixing the position of said coil portion of said springrelative to one portion of said air distribution plenum;

alignment means for maintaining at least a portion of said free end portion of said wound coil spring positioned in an arcuate path having a desired constant minimum radius with respect to said pivot axis whereby said spring offers minimal interference to the passage of air through said bushing and whereby the forces generated by said spring at each end thereof are maintained substantially constant and in directions which are at respective substantially constant angles to the respective radii of the points of attachment of said spring within a predetermined range of relative angular positions between said'head assembly and said head support assembly to counter-balance said head assembly against the forces of gravity.

12. A hair dryer as defined in claim 11 wherein said free endof said spring is secured to said other portion of said air distribution. plenum by means of a spring support bracket, said bracket having one end fixed with respect to said' other portion of said plenum and its other end attached to said free end of said spring, and being positioned to direct the forces generated by said spring in a direction which opposes the tendency of said head assembly to pivot downwardly under the influence of gravity, and wherein said spring is selected from among springstrips having a substantially constant pull within a predetermined range of deformation such thatsaid influence of gravity is counter-balanced.

13. A hair dryer as defined in claim 11 wherein said bushing also includes axially extending spring-guide means positioned radially inwardly of said free end portion of said spring for maintaining said free end portion within an arc having a desired minimum radius regardless of the extent of extension of said spring.

14. A portable hair dryer as defined in claim 12 wherein individual cylindrical bushings are provided between respective ones of said adjacent inlet and outlet ports, and in which said bushings are bilaterally symmetrical with respect to a plane passing axially through said bushings, and wherein said spring mounting post, said spring and said spring attachment means are provided adjacent each of said bushings at opposite sides of said head mounting assembly and are mirror images of each other.

15. A hair dryer having a head support assembly which is upstanding when the dryer is in an operating configuration, and a rigid dryer head assembly which is adapted to receive a portion of the head of a user therein and which is pivotally mounted on said head support assembly for pivoting about a hotizontal axis of pivot, said head support assembly being a first pivotal element and said head assembly being a second pivotal element; said hair dryer further having counterbalancing means for maintaining said head assembly in any desired operating position, saidcounter-balancing means including elongatable tension means having at least two ends, and having the characteristic of exerting a substantially constant tension regardless of extent of the other end of said tension means to the other of said elements, said first and second attachment means being in a common planelperpendicular to the axis of pivot; means for maintaining said tension means in an operating path in which forces generated by the tension meansare maintained directed at each end thereof in directions which are atrespective constant angles with respect to each respective radius from thepivot axis to respective first and second points of attachment regardless of position of the head'assembly, and wherein the tension means'exerts sufficient tension to counter balance the gravity-induced tedency of the head assembly to pivot.

16. A hair dryer as defined in claim 15 wherein said counter-balancing means include: a spring-winding post fixed with respect to one of saidrelements, said post extending parallel to the pivot axis into the other of said elements; a spring formed from anelongated strip of spring metal, said spring, in its relaxed condition, being in the form of a tightly wound coil spring having a coiled portion with a' central opening. and a free end portion extending from" the periphery of the coil portion, said post passing through said central opening of said coil, and said free end of said spring being secured with respect to said other element of said dryer.

17. A hair dryer as defined in claim 16 which further includes spring-guide means comrising an axially extending element which is fixed with respect to said'one of said elements, and which extends into said other, of

said elements to aposition radially inwardly of saidfreeend of said spring, said spring guide means defining an arcuate operating path for said free end having a constant minimum radius withrespect to said axis'of pivot.

18. A hair dryer as defined in claim 15 wherein said constant angle is a substantially right angle with respect to the radius at the innermost of said attachment means.

19. A hair dryer as defined in claim 15 wherein aid counter-balancing means include a spring and springguide means, said spring-guide means being fixed with respect to one of said elements and extending axially into the other of said elements substantially parallel with said pivot axis along a path radially inwardly of an extended portion of said spring, and being positioned for engaging a radially inwardly facing portion of said spring for confining said spring in an arcuate region having a desired constant inner radius with respect to said pivot axis.

20. The dryer of claim 15 wherein said head assembly includes a pair of opposed spaced-apart annular first coupling elements having a fixed distance therebeto one of said elements extend through said. coupling elements into the other element.

Claims

1. In a hair dryer of the type which includes a head assembly having a defined region for receiving a portion of the head of a user and a C-shaped first portion of an air distribution plenum for directing air onto said defined region, said first portion of said air distribution plenum having axially-aligned annular inlet ports at either end thereof for receiving air under pressure; a head support assembly including a generally horizontal second portion of said air distribution plenum and a source of air under Pressure, said second portion of said air distribution plenum communicating with said air source and having a pair of horizontally-opposed annular outlet ports axially aligned with respective ones of said annular inlet ports; and coupling means comprising at least one cylindrical bushing extending between adjacent ones of said axially aligned inlet and outlet ports for bridging the gaps between the inlet ports of said C-shaped first plenum portion and the outlet ports of said second plenum portion to deliver air from said source to said head receiving region, said coupling means establishing a generally horizontally disposed pivot axis between said head assembly and said head support assembly coaxial with said inlet and outlet ports; an improved counter-balancing assembly for said head assembly comprising: tension means comprising at least one wound coil spring positioned in a plane perpendicular to said pivot axis; first attachment means for fixing the position of one end of said spring relative to said head assembly; second attachment means for fixing the position of the other end of said spring relative to said head support assembly; and alignment means for maintaining at least a portion of said wound coil spring positioned in an arcuate path having a desired constant minimum radius with respect to said pivot axis whereby said spring offers minimal interference to the passage of air through said bushing and whereby the forces generated by said spring at each end thereof are maintained substantially constant and in directions which are at respective substantially constant angles to the respective radii of the points of attachment of said spring within a predetermined range of relative angular positions between said head assembly and said head support assembly to counter-balance said head assembly against the forces of gravity.

3. The hair dryer of claim 1 in which said alignment means include spring-guide means fixed with respect to one of said portions of said air distribution plenum and extending axially into the other portion of said plenum along a path radially inwardly of said constant radius portion of said wound coil spring for engaging a radially inwardly facing portion of said spring to confine said portion of said spring in an arcuate region having said desired constant inner radius with respect to said pivot axis.

5. The hair dryer defined in claim 1 wherein said bushing extends between said first portion and said second portion of said air distribution plenum, and wherein said bushing has keying means cooperating with one of said plenum portions to fix said bushing with respect to said portion, and wherein said bushing also includes a portion thereof positioned in the other of said plenum portions providing attachment means for one end of said wound coil spring, and wherein said bushing includes rigid guide means positioned radially inwardly of said spring to engage the radially inward extreme of said spring to maintain at least a portion of the portion of said spring extending between said first and second attachment means in an arcuate path having a minimum desired radius with respect to the axis of pivot of said head assembly and said head support assembly.

6. In a hair dryer of the type which includes a head assembly having a defined region for receiving a portion of the head of a user and a C-shaped first portion of an air distribution plenum for directing air onto said defined region, said first portion of said air distribution plenum having axially-aligned annular inlet ports At either end thereof for receiving air under pressure; a head support assembly including a generally horizontal second portion of said air distribution plenum and a source of air under pressure, said second portion of said air distribution plenum communicating with said air source and having a pair of horizontally-opposed annular outlet ports axially aligned with respective ones of said annular inlet ports; and coupling means comprising at least one cylindrical bushing extending between adjacent ones of said axially-aligned inlet and outlet ports for bridging the gaps between the inlet ports of said C-shaped first plenum portion and the outlet ports of said second plenum portion to deliver air from said source to said head receiving region, said coupling means establishing a generally horizontally disposed pivot axis between said head assembly and said head support assembly coaxial with said inlet and outlet ports; an improved counter-balancing assembly for said head assembly comprising: tension means comprising an elongated strip of spring metal having a tightly wound coil portion with a central opening and a free end portion extending from the periphery of said coil portion, said spring being positioned in a plane perpendicular to said pivot axis adjacent said cylindrical bushing; first attachment means comprising a spring winding post extending through said central opening for fixing the position of said coil portion of said spring relative to one portion of said air distribution plenum; second attachment means for fixing the position of said free end portion of said spring relative to the other portion of said air distribution plenum; and alignment means for maintaining said free end portion of said spring positioned in an arcuate path having a desired constant minimum radius with respect to said pivot axis greater than the radius of said cylindrical bushing whereby said spring offers minimal interference to the passage of air through said bushing and whereby the forces generated by said spring at each end thereof are maintained substantially constant and in directions which are at respective substantially constant angles to the respective radii of the points of attachment of said spring within a predetermined range of relative angular positions between said head assembly and said head support assembly to counter-balance said head assembly against the forces of gravity.

7. A hair dryer as defined in claim 6 which further includes spring-guide means comprising at least one axially extending element which is fixed with respect to said one of said portions of said air distribution plenum, and which extends into said other of said portions to a position radially inwardly of said free end portion of said spring, said spring guide means urging said spring into said arcuate path whereby said free end portion has a constant minimum radius with respect to the axis of rotation of said head assembly and said head support assembly.

9. A hair dryer as defined in claim 6 wherein individual cylindrical bushings are provided between adjacent ones of said inlet and outlet ports, wherein said tension means comprise a pair of wound coil strips adjacent each of said bushings, and wherein said attachment means are provided for each of said coil strips.

10. A hair dryer as defined in claim 6 which further includes key means for securing said bushing to one of said plenum portions, and wherein said bushing includes said spring winding post integral therewith, and wherein said bushing also includes axially extending springguide means extending to a position radially inwardly of said free end of said spring for urging the free end portion of said spring into said arcuate path.

11. A hair dryer comprising, in combination: a head assembly having a defined region for receiving a portion of the head of a user and a C-shaped first portion of an air distribution plenum for directing air onto said defined region, said first portion of said air distribution plenum having axially-aligned annular inlet ports at either end thereof for receiving air under pressure; a head support assembly including a generally horizontal second portion of said air distribution plenum and a source of air under pressure, said second portion of said air distribution plenum communicating with said air source and having a pair of horizontally-opposed annular outlet ports axially aligned with respective ones of said annular intake ports; coupling means comprising at least one cylindrical bushing extending between adjacent ones of said axially-aligned inlet and outlet ports for bridging the gaps between the inlet ports of said C-shaped first plenum portion and the outlet ports of said second plenum portion to deliver air from said source to said head receiving region, said coupling means establishing a generally horizontally disposed pivot axis between said head assembly and said head support assembly coaxial with said inlet and outlet ports; tension means including a wound coil spring having, in its relaxed position, a tightly wound coil portion having a center opening, and a free end portion extending therefrom, said spring being positioned in a plane perpendicular to said pivot axis; first attachment means including a spring winding post extending through said center opening for fixing the position of said coil portion of said spring relative to one portion of said air distribution plenum; second attachment means for fixing the position of said free end portion of said spring relative to the other portion of said air distribution plenum; and alignment means for maintaining at least a portion of said free end portion of said wound coil spring positioned in an arcuate path having a desired constant minimum radius with respect to said pivot axis whereby said spring offers minimal interference to the passage of air through said bushing and whereby the forces generated by said spring at each end thereof are maintained substantially constant and in directions which are at respective substantially constant angles to the respective radii of the points of attachment of said spring within a predetermined range of relative angular positions between said head assembly and said head support assembly to counter-balance said head assembly against the forces of gravity.

12. A hair dryer as defined in claim 11 wherein said free end of said spring is secured to said other portion of said air distribution plenum by means of a spring support bracket, said bracket having one end fixed with respect to said other portion of said plenum and its other end attached to said free end of said spring, and being positioned to direct the forces generated by said spring in a direction which opposes the tendency of said head assembly to pivot downwardly under the influence of gravity, and wherein said spring is selected from among spring strips having a substantially constant pull within a predetermined range of deformation such that said influence of gravity is counter-balanced.

15. A hair dryer having a head support assembly which is upstanding when the dryer is in an operating configuration, and a rigid dryer head assembly which is adapted to receive a portion of the head of a user therein and which is pivotally mounted on said head support assembly for pivoting about a hotizontal axis of pivot, said head support assembly being a first pivotal element and said head assembly being a second pivotal element; said hair dryer further having counterbalancing means for maintaining said head assembly in any desired operating position, said counter-balancing means including elongatable tension means having at least two ends, and having the characteristic of exerting a substantially constant tension regardless of extent of elongation of said tension means within an operating range of elongation thereof; first attachment means for attaching one end of said tension means to one of said elements, and second attachment means for attaching the other end of said tension means to the other of said elements, said first and second attachment means being in a common plane perpendicular to the axis of pivot; means for maintaining said tension means in an operating path in which forces generated by the tension means are maintained directed at each end thereof in directions which are at respective constant angles with respect to each respective radius from the pivot axis to respective first and second points of attachment regardless of position of the head assembly, and wherein the tension means exerts sufficient tension to counter-balance the gravity-induced tedency of the head assembly to pivot.

16. A hair dryer as defined in claim 15 wherein said counter-balancing means include: a spring-winding post fixed with respect to one of said elements, said post extending parallel to the pivot axis into the other of said elements; a spring formed from an elongated strip of spring metal, said spring, in its relaxed condition, being in the form of a tightly wound coil spring having a coiled portion with a central opening and a free end portion extending from the periphery of the coil portion, said post passing through said central opening of said coil, and said free end of said spring being secured with respect to said other element of said dryer.

17. A hair dryer as defined in claim 16 which further includes spring-guide means comrising an axially extending element which is fixed with respect to said one of said elements, and which extends into said other of said elements to a position radially inwardly of said free end of said spring, said spring guide means defining an arcuate operating path for said free end having a constant minimum radius with respect to said axis of pivot.

19. A hair dryer as defined in claim 15 wherein aid counter-balancing means include a spring and spring-guide means, said spring-guide means being fixed with respect to one of said elements and extending axially into the other of said elements substantially parallel with said pivot axis along a path radially inwardly of an extended portion of said spring, and being positioned for engaging a radially inwardly facing portion of said spring for confining said spring in an arcuate region having a desired constant inner radius with respect to said pivot axis.

20. The dryer of claim 15 wherein said head assembly includes a pair of opposed spaced-apart annular first coupling elements having a fixed distance therebetween, said first coupling elements being substantially concentric with the pivot axis; wherein at least a portion of said second pivotal element is positioned between said opposing spaced-apart annular first coupling elements; and wherein said second pivotal element has oppositely facing annular second coupling elements aligned with and each Engaging a respective first coupling element, and wherein said counter-balancing means are provided at each respective apir of opposing annular first and second coupling elements, and wherein one of said attachment means fixed to one of said elements extend through said coupling elements into the other element.