EP2555650B1

EP2555650B1 - Motorised hair styling iron

Info

Publication number: EP2555650B1
Application number: EP11765055.6A
Authority: EP
Inventors: Wai Ho Michael Keong; Wai Keung Kent Wan
Original assignee: Kenford Industrial Co Ltd
Current assignee: Kenford Industrial Co Ltd
Priority date: 2010-04-09
Filing date: 2011-04-07
Publication date: 2019-03-06
Anticipated expiration: 2031-04-07
Also published as: CN201822159U; EP2555650A1; US20130025620A1; WO2011124137A1; EP2555650A4

Description

Technical field

The present invention relates to hair styling irons, particularly electric appliances for hair curling or straightening, having one member motor driven to rotate or vibrate.

Background of the Invention

One type of known hand-held electric hair curling or straightening iron use two jaws or arms, at least one of which is heated, with the other cooperating to hold hair in contact with the first, and being moveable from an open position allowing the insertion of hair to a closed position to put the hair in contact with the heater.
Some of the drawbacks with the prior art hair irons are that the processing results can be variable, if the operation is performed too fast, the processing time is too short and, therefore, the hair is not properly formatted, while moving too slowly can damage the hair by overheating. Operation of these irons requires the user to carefully manipulate the two jaws. A new user unfamiliar with the iron may have difficulty in accurately controlling the hair-gripping forces that vary with the clamping pressure between the heating body and hair. As a tool with opposing smooth and hard clamping faces is drawn through the hair any variation in the user's hold on the tool produces a variable contact pressure that can cause discomfort, as the hair is pulled unevenly. The resulting treatment of a lock of hair may also produce an uneven appearance.
One way in which this issue has been addressed in old hair irons is by providing one of the jaws with a brush or comb for gripping the hair, however such a brush or comb makes the tool less compact and can restrict the manner in which the tool can be used for different operations, such as curling and straightening.
EP 1 698 249 describes a hair iron having a "buffer member" which is located in between two opposing steel plates to allow hair passing through the steel plates to be straightened. EP 1 991 083 describes a hair styling tool including a body, a cylinder extending from the body, wherein the cylinder is rotatable relative to the body by means of a motor.
It will be understood that there is a need to provide a hair styling iron capable of readily being used by new users to achieve hair shaping of good quality, durability, and with uniform appearance throughout the hair, while being easy to use and convenient. The apparatus should capable of ensuring a good thermal transfer between the heated part of the apparatus and hair, while ensuring the protection thereof and with greater reliability in operation. The apparatus should be capable of ensuring a good contact pressure between the means of shaping and hair during treatment. The device should have a simple and compact structure that can be manufactured for a low cost. It is an object of the present invention to address the above needs or more generally to provide an improved electric hair iron.

Disclosure of the Invention

According to one aspect of the present invention there is provided a hair styling iron in accordance with claim 1, the iron comprising:

a pair of elongate jaws, each jaw having proximal and distal parts;
a hinge connecting the proximal parts of the jaws for movement between a closed position in which the jaws are adjacent for grasping hair therebetween and an open position in which the jaws are spaced apart;
motorised means for rotating at least one of the jaws;
heating means for heating at least one of the jaws;
the distal parts of the jaws having complementary hair-engaging surfaces configure to hold and engage hair therebetween, and wherein
two elastomeric ribs extend along one of the hair-engaging surfaces.

With the jaws closed, the substantially cylindrical hair-engaging surface and concave hair-engaging surface are adjacent and oppose one another in a generally parallel configuration.
The proximal parts may be at longitudinal ends of the jaws or, for instance, at positions intermediate the longitudinal ends.
The pair of jaws comprises first and second jaws, the first jaw includes a barrel having a first longitudinal axis and a substantially cylindrical hair-engaging surface,
the motorised means comprises a rotary motor which rotates the barrel about the first longitudinal axis and wherein
the one of the hair-engaging surfaces comprises a concave hair-engaging surface formed on the second jaw.
The two elastomeric ribs are disposed adjacent opposing longitudinal edges of the concave hair-engaging surface and project beyond the concave hair-engaging surface.
Preferably each of the elastomeric ribs is linear and extends generally parallel to a longitudinal axis of the jaw on which it is disposed. Optionally the at least one elastomeric rib may be curvilinear.
Preferably each of the elastomeric ribs is linear and extends substantially parallel to a surface of the barrel in the closed position.
Preferably the hair-engaging surfaces are metal surfaces, each of the elastomeric ribs has a substantially constant cross-section throughout its length, and protrudes from the one of the hair-engaging surfaces by a substantially constant dimension throughout its length.
Preferably each of the two elastomeric ribs has a convex outer surface protruding from the one of the hair-engaging surfaces. Optionally, the outer surface of the rib may protrude from the one of the hair-engaging surfaces only when the heating portion is at an elevated temperature, due to thermal expansion, and may otherwise be flush or recessed below the one of the hair-engaging surfaces.
Preferably the convex outer surface of each of the elastomeric ribs has a substantially constant radius of curvature.
Each of the elastomeric ribs may be bonded to the one of the hair-engaging surfaces. Alternatively, each of the elastomeric ribs may be formed on a strip received in an elongate slot in the one of the hair-engaging surfaces.
Each jaw may have an elongate heating portion. Preferably the heating portion has a longitudinally extending plane of symmetry and each elastomeric rib is located substantially symmetrically relative to the plane of symmetry. For instance, where two ribs are provided, they may be disposed either side of the plane.
Preferably the width of each of the elastomeric ribs is between 2% and 20% of the width of the one of the hair-engaging surfaces. Preferably each of the elastomeric ribs has a hardness between 30 Shore A and 50 Shore D. Preferably the at least one elastomeric rib is formed from a silicon rubber.
Optionally, both elongate heating portions may have substantially the same form with respective each of the elastomeric ribs.
This invention provides hair iron which is particularly effective in use with the above-described method. The iron may be economically constructed and has an overall simple design which minimizes manufacturing costs and maximizes performance, allowing the user to draw the tool through the hair with a generally constant hair-gripping force.

Brief Description of the Drawings

Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings, wherein:

Figure 1 is a perspective view of a hair styling iron out of the scope of the present invention shown in an open position;
Figure 2 is an end view of the iron of Fig. 1 in a closed position;
Figure 3 is a side view corresponding to Fig. 2;
Figure 4 is an enlarged fragmentary cross section through the second jaw of the iron of Fig. 1;
Figure 5 is a perspective view of a hair styling iron according to an embodiment of the invention, shown in an open position, and
Figure 6 is an enlarged fragmentary cross section through the second jaw of the iron of Fig. 5.

Description of the Preferred Embodiments

Referring to the drawings, Fig. 1 illustrates a hand held electric hair iron out of the scope of the present invention having first and second elongate jaws 10, 11 joined at respective proximal parts disposed near their longitudinal ends by a transverse hinge 12, shown in an open position. Both jaws 10, 11 are of hollow construction, with the first jaw 10 including a barrel 14 disposed at its outer end and a coaxial handle section 15 at its inner end. The barrel 14 has a first longitudinal axis 13 and a substantially cylindrical hair-engaging surface 16.
In the iron illustrated, the barrel 14 is heated by an internally enclosed resistive element (not shown). Further, the barrel 14 is motor-driven to rotate about the longitudinal axis 13, or to vibrate, either generally omni-directionally or linearly or rotationally along/about an axis. Motorised hair irons having a jaw driven to rotate or vibrate are known from the prior art, and it will be understood that this can be achieved in a number of different ways. Power may be supplied to the heating element and motor via a power cord 17 (shown partially cut away).
The second jaw 11 has a distal part with a concave hair-engaging surface 19 which is elongate and part-cylindrical. The concave hair-engaging surface 19 is complementary to the surface 16 of the barrel 14, and with the jaws 10, 11 closed the hair-engaging surfaces 16, 19 are adjacent and oppose one another in a generally parallel configuration.
In Figs 1-3, an elastomeric rib 20 extends centrally along the concave hair-engaging surface 19 from which it projects. The exposed face 21 of the rib 20 may have a smooth convex form, such as a constant radius of curvature. The elastomeric rib 20 may be located in a linear slot in the plate 22. A central plane 23 extends longitudinally and bisects the jaws 10, 11. The elastomeric rib 20 may be located at the trough of the concave face 19, such that it is also bisected by the plane 23. In the iron illustrated, the rib 20 protrudes from the concave face by a substantially constant dimension throughout its length (of between 0.1mm and 1mm). The longitudinal ends of the rib 20 are spaced apart from the longitudinal ends of the plate 22.
The basic structure of the jaws 10, 11 may be a moulded polymeric construction forming the handle portions 15, while the barrel 14 and plate 22 are of metal such as chromium steel, and their respective faces 16, 19 are polished.
An embodiment of the second jaw according to the present invention is shown in Figs 5 and 6, in which a pair of parallel, generally coextensive, elastomeric ribs 20a are provided, each disposed adjacent opposing longitudinal edges of the hair-engaging surface 19, such that their exposed faces 21a project beyond the surface 19. The ribs 20a are disposed symmetrically on opposing sides of the central plane 23.
In preferred embodiments the width of the rib 20, 20a is between 2% and 20% of the width of the concave face 19, most preferably between 5% and 10% of the width of the face 19. Ribs 20, 20a of silicon rubber having a hardness of 40 Shore A has been found to provide good performance, but satisfactory performance can be obtained with a hardness between 30 Shore A and 50 Shore D.
In use, a lock of hair is wound in a loop about the elongate barrel 14, the user grasping the jaws to clamp the lock of hair between the faces 16, 19. In this manner the hair is pressed against the rib(s) 20, 20a while it is softened by the application of heat. The user then draws the iron along the lock of hair to form the hair, and the or each elastomeric rib allows the hair-gripping force to be more readily maintained at a constant level.
Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope of the appended claims.

Claims

A hair styling iron, comprising:
a pair of elongate jaws comprising first and second jaws (10, 11), each jaw (10, 11) having proximal and distal parts, the distal parts of the jaws (10, 11) having complementary hair-engaging surfaces (16, 19) configured to hold and engage hair therebetween, one of the hair-engaging surfaces (16, 19) comprising a concave hair-engaging surface (19) formed on the second jaw (11), the first jaw (10) including a barrel (14) having a first longitudinal axis (13) and a substantially cylindrical hair-engaging surface (16);

a hinge (12) connecting the proximal parts of the jaws (10, 11) for movement between a closed position in which the jaws (10, 11) are adjacent for grasping hair therebetween and an open position in which the jaws (10, 11) are spaced apart;

motorised means for rotating at least one of the jaws (10, 11), the motorised means comprising a rotary motor which rotates the barrel (14) about the first longitudinal axis (13);

heating means for heating at least one of the jaws (10, 11); and

two elastomeric ribs (20a) extending along one of the hair-engaging surfaces (16, 19) and disposed adjacent opposing longitudinal edges of the concave hair-engaging surface (19) and projecting beyond the concave hair-engaging surface (19);
wherein with the jaws (10, 11) closed the substantially cylindrical hair-engaging surface (16) and concave hair-engaging surface (19) are adjacent and oppose one another in a generally parallel configuration.
The iron of claim 1 wherein each of the elastomeric ribs (20a) is linear and extends generally parallel to a longitudinal axis of the jaw (10, 11) on which it is disposed.
The iron of claim 2 wherein each of the two elastomeric ribs (20a) extend substantially parallel to a surface of the barrel (14) in the closed position.
The iron of any one of claims 1-3 wherein the hair-engaging surfaces (16, 19) are metal surfaces, each of the elastomeric ribs (20a) has a substantially constant cross-section throughout its length, and protrudes from the one of the hair-engaging surfaces (16, 19) by a substantially constant dimension throughout its length.
The iron of claim 4 wherein the substantially constant dimension is between 0.1 mm and 2 mm.
The iron of claim 5 wherein each of the two elastomeric ribs (20a) has a convex outer surface (21a) protruding from the one of the hair-engaging surfaces (16, 19).
The iron of claim 6 wherein the convex outer surface (21a) of each of the two elastomeric ribs (20a) has a substantially constant radius of curvature.
The iron of any one of claims 1-7 wherein each of the two elastomeric ribs (20a) is bonded to the one of the hair-engaging surfaces (16, 19).
The iron of any one of claims 1-7 wherein each of the two elastomeric ribs (20a) is formed on a strip received in an elongate slot in the one of the hair-engaging surfaces (16, 19).
The iron of any one of claims 1-9 wherein each jaw (10, 11) has an elongate heating portion.
The iron of claim 10 wherein the heating portion has a longitudinally extending plane of symmetry (23) and each elastomeric rib (20a) is located substantially symmetrically relative to the plane of symmetry (23).
The iron of claim 11 wherein the hair-engaging surfaces (16, 19) are polished metal surfaces.
The iron of claim 12 wherein the width of each of the two elastomeric ribs (20a) is between 2% and 20% of the width of the one of the hair-engaging surfaces (16, 19).
The iron of claim 13 wherein each of the two elastomeric ribs (20a) has a hardness between 30 Shore A and 50 Shore D.
The iron of any one of claims 1-14 wherein each of the two elastomeric ribs (20a) is formed from a silicon rubber.