U.S. patent application number 10/275600 was filed with the patent office on 2004-02-12 for jewelry arrangements.
Invention is credited to Holemans, Thierry, Stalmans, Rudy.
Application Number | 20040025984 10/275600 |
Document ID | / |
Family ID | 8179977 |
Filed Date | 2004-02-12 |
United States Patent
Application |
20040025984 |
Kind Code |
A1 |
Holemans, Thierry ; et
al. |
February 12, 2004 |
Jewelry arrangements
Abstract
A piece of jewelry (10) is disclosed, comprising first and
second substantially opposing end portions (14, 16), at least one
said end potion being moveable from an open state A in which said
end portions (14, 16) are spaced apart towards a closed state B in
which said end portions (14, 16) are spaced apart by, a reduced gap
or are substantially engaged. The piece of jewelry (10) comprises
at least a section (12a) made from a shape memory material and said
shape memory material is adapted, at or above a predetermined
temperature Ta, to bring said end portions (14, 16) towards each
other. This occurs preferably when said shape memory material is
placed in the region of a body part of a wearer such that shape
memory effect is used in co-operation with body temperature to fit
said piece of jewelry to its wearer whist simultaneously causing, a
change in externally visible shape or configuration or the
jewelry.
Inventors: |
Holemans, Thierry;
(Bruxelles, BE) ; Stalmans, Rudy; (Belgium,
DE) |
Correspondence
Address: |
William M Lee Jr
Lee Mann Smith McWilliams
Sweeney & Ohlson
PO Box 2786
Chicago
IL
60690-2786
US
|
Family ID: |
8179977 |
Appl. No.: |
10/275600 |
Filed: |
July 7, 2003 |
PCT Filed: |
March 6, 2002 |
PCT NO: |
PCT/EP02/02456 |
Current U.S.
Class: |
148/563 ;
148/402 |
Current CPC
Class: |
A44C 27/003 20130101;
A44C 15/005 20130101; C22F 1/006 20130101; C22C 5/02 20130101; A44C
15/00 20130101; C22C 9/00 20130101; C08L 2201/12 20130101; A44C
27/008 20130101; A44C 5/20 20130101; A44C 5/0092 20130101; A44C
5/0084 20130101; A44C 27/001 20130101 |
Class at
Publication: |
148/563 ;
148/402 |
International
Class: |
C22F 001/00; C22K
001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 8, 2001 |
EP |
01200868.6 |
Jan 25, 2002 |
GB |
0201720.0 |
Claims
1. A piece of jewelry comprising first and second substantially
opposing end portions, said piece of jewelry comprising at least a
section made from a shape memory material adapted above a
predetermined temperature to use shape memory effect so as to cause
automatically relative movement between said end portions from an
open state, in which said end portions are spaced apart by a gap
adapted for fittment of said jewelry, towards a closed state in
which said gap is reduced such that said jewelry is fitted.
2. A piece of jewelry according to claim 1, wherein said relative
movement is adapted to result in a change to an externally visible
shape or configuration of said piece of jewelry.
3. A piece of jewelry according to claim 1 or claim 2, wherein a
said predetermined temperature for end portion closure lies in the
region of a body temperature of a wearer of said jewelry.
4. A piece of jewelry according to any preceding claim, wherein
said shape memory material exhibits thermal hysteresis having upper
and lower temperature transformation ranges, said upper temperature
transformation comprising a range of 10.degree. C. or less,
preferably 7.degree. C. or less and more preferably 5.degree. C. or
less.
5. A piece of jewelry according to claim 4, wherein said shape
memory material has an upper transformation start temperature As in
the range 18.degree. C. to 23.degree. C.
6. A piece of jewelry according to claim 4 or claim 5, wherein said
shape memory material has an upper transformation finish
temperature A.sub.f in the range 23.degree. C. to 30.degree. C.
7. A piece of jewelry according to any preceding claim, wherein
said shape memory material comprises a stabilized shape memory
material, trained and adapted for repeated movement between said
open and closed states.
8. A piece of jewelry according to any preceding claim, wherein
removal of said piece of jewelry from a wearer is restricted once
said jewelry has substantially moved into said closed state.
9. A piece of jewelry according to any preceding claim, wherein
said piece of jewelry is adapted in said closed state to at least
one of partially capture, grip, pass through or enclose a body part
of a said wearer.
10. A piece of jewelry according to any preceding claim, wherein
said relative movement is adapted to occur substantially in one
plane.
11. A piece of jewelry according to any preceding claim, wherein
said relative movement is adapted to bring said end portions into
engagement, in which state said end portions are in at least
partial abutment with a clamping force therebetween.
12. A piece of jewelry according to claim 11, wherein one or both
said end portions comprise a locating arrangement adapted to align
said end portions in a substantially predetermined relationship
when said end portions are engaged.
13. A piece of jewelry according to claim 11 or claim 12, further
comprising a latching means adapted to latch said end portions into
said closed state at least temporarily and preferably
removably.
14. A piece of jewelry according to any one of claims 11 to 13,
further comprising an indicator arrangement adapted to indicate
when said end portions are at least one of open or closed.
15. A piece of jewelry according to claim 14, wherein said
indicator arrangement comprises indicia which is at least one of
displayed or hidden when said jewelry is in said closed state.
16. A piece of jewelry according to any preceding claim, wherein
said shape memory section is adapted to move said end portions in a
substantially pivotal manner.
17. A piece of jewelry according to any preceding claim, wherein
said piece of jewelry is adapted to be gripped or pulled on at
least a predetermined section and in such a manner that a gripping
or pulling force above a predetermined level moves said piece of
jewelry towards said open state.
18. A piece of jewelry according to claim 17, wherein said end
portions are adapted to be opened from a closed state under the
influence of a said predetermined level of force applied below a
predetermined temperature at which said shape memory material
adopts a pseudo-elastic state.
19. A piece of jewelry according to any preceding claim, wherein
said piece of jewelry comprises an inactive section, which may be
substantially devoid of shape memory material, such that said piece
of jewelry is adapted to be handled by said inactive section
substantially without changing shape for at least a predetermined
time period, so as for example to enable manual fittment.
20. A piece of jewelry according to any preceding claim, wherein
said piece of jewelry comprises an ornamental band whose said open
state comprises a substantially elliptical or enlarged circular
open-ended shape and whose closed state comprises a reduced gap
open-ended shape or a substantially closed shape.
21. A piece of jewelry according to any preceding claim, wherein
said piece of jewelry comprises a ring whose said open state
comprises a substantially elliptical or enlarged circular
open-ended shape and whose closed state comprises a substantially
closed circle.
22. A storage and/or fitting arrangement for a piece of jewelry
according to any preceding claim, said arrangement comprising a
temperature varying device adapted to bring a said piece of jewelry
to or beyond a temperature at which said piece is moveable into
said open state.
23. An arrangement according to claim 22, wherein said temperature
varying device comprises a cooling chamber adapted to receive a
said piece of jewelry and a heat exchange means adapted to reduce
the temperature of said piece in said chamber.
24. An arrangement according to claim 22 or claim 23, wherein said
heat exchange means comprises an electrically operated heat sink
apparatus, preferably portable and adapted for battery
operation.
25. An arrangement according to any one of claims 22 to 24, further
comprising a biasing means adapted to bias a ring therein towards
said open state.
26. A method of producing a piece of jewelry, including: a)
providing an elongate piece of material comprising at least a
section which includes a shape memory material; b) forming on
opposing ends of said piece of material first and second end
portions; c) forming said piece of material into an open state
adapted for fittment to a body part of a wearer and in which open
state said end portions substantially face each other spaced apart
by a gap; and d) adapting said shape memory material to move at
least one said end portion, above a predetermined temperature,
towards a closed state in which said gap is reduced or said end
portions are substantially engaged, whereby shape memory effect is
used for fitting said piece of jewelry to a wearer whilst
simultaneously changing an externally visible shape or
configuration of said piece of jewelry.
27. A method according to claim 26, including stabilizing said
shape memory portion for repeated movement of said end portions
between said open and closed states, preferably stabilizing said
shape memory material by training.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to jewelry arrangements and in
particular to jewelry which incorporates at least a section formed
from a shape memory material, such as a shape memory alloy. The
present invention also relates to methods of producing and
arrangements for fitting such jewelry.
BACKGROUND TO THE INVENTION
[0002] It is known to provide jewelry that is at least one of
partially captive on, gripping, passing through or enclosing a body
part of a wearer. A non-exhaustive list of such jewelry includes
forms of finger ring, bracelet, earring necklace,
watch-strap/bracelet and some body piercing ornamentation. Problems
can arise in fitting some of these types of jewelry or in retaining
it in place.
[0003] In the case of jewelry rings, such as finger rings used for
example to signify marriage, the ring may be placed by one partner
onto the finger of the other partner during a ceremony. This act
traditionally carries great significance, although in many cases
the ring is a simple band of gold, perhaps inscribed. Simplicity in
appearance of the wedding ring is a feature that many couples like
to preserve. In the world of jewelry and fashion design it is
desirable to seek, but difficult to find, interpretations of long
established themes such as the wedding ring whilst maintaining
traditional values.
[0004] There are other problems relating to rings one of which
concerns swelling of the finger, which may be caused by illness or
accidents such as crushing, impact or burns. It may then become
difficult to remove a ring and possible further injury could occur,
e.g. due to reduced blood circulation. Under such circumstances, it
is known for a ring to be cut or deformed so as to remove it and it
may never regain its original shape or significance after repair or
may even become totally unusable. Furthermore, some potential
wearers may have deformed or otherwise misshapen ring fingers and
may experience difficulties in finding and fitting/removing
suitable rings.
[0005] Similar problems can be envisaged in relation to some other
pieces of jewelry such as ornamental bands, which includes
bracelets. For example, the bangle type of bracelet is often of a
rigid and substantially circular or elliptical shape, although
other shapes such as polygons with various numbers of sides may
also be used. In order to be captive on a wrist, the cross-section
of the bracelet is often smaller than the open hand of a wearer. If
a potential wearer has a large hand but small wrist, putting on a
rigid and closed bracelet may prove inconvenient. In addition, some
rigid bracelets and earrings are openable and include swinging
hinge and latching arrangements adapted for manual operation, which
may prove tricky to use and may be easily damaged.
[0006] It is clearly desirable to seek arrangements that may help
alleviate the practical problems discussed above, any such solution
being technically competent and simple to use. In doing so it
should be remembered that the market dictates any solution offered
should also be stylish, whether that involves new concepts in
aesthetics or the maintenance of traditional values.
[0007] In EP-031070 helical jewelry bands such as rings or
bracelets are formed from overlapping wound sections of shape
memory wire. These bands may carry ornamentation and use shape
memory material in a super-elastic state so as to retain shape
whilst being worn, temperature changes not being necessary for
fitting, wearing or removal. Once it has been put on, the jewelry
of EP-0313070 acts as a static display. Although it may be
temporarily deformed during fitting, this jewelry uses only the
super-elastic properties of shape memory material and then only for
its configuration into a condition suitable for being worn and for
shape retention. It will be noted that the gauge of wire used in
this arrangement is quite thin (e.g. 0.7 mm diameter) and that the
bands can be expanded for fitting using a low force. Removal of
this low force allows the bands to return towards their original
shape, which in free space they should achieve. Since only a low
force is required to open the super elastic element, the jewelry
can be worn by people having different sizes or body part, e.g.
finger or wrist. In the event that a body part such as a wrist is
thicker than the inner diameter of the ring/bracelet, then the
super elastic element will only exert a gentle pressure on that
body part due to the thin gauge of the constituent shape memory
wire.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide improved
jewelry arrangements; in particular to provide improved jewelry
arrangements that incorporate at least a portion formed from a
shape memory material such as a shape memory alloy. It is a further
object of the present invention to provide improved arrangements
for producing and fitting such jewelry.
[0009] Accordingly, the present invention provides a piece of
jewelry comprising first and second substantially opposing end
portions, said piece of jewelry comprising at least a section made
from a shape memory material adapted above a predetermined
temperature to use shape memory effect so as to cause automatically
relative movement between said end portions from an open state, in
which said end portions are spaced apart by a gap adapted for
fittment of said jewelry, towards a closed state in which said gap
is reduced such that said jewelry is fitted.
[0010] Said relative movement may be adapted to result in a change
to an externally visible shape or configuration of said piece of
jewelry. Said relative movement may be adapted to occur in one
plane, such that for example said jewelry is non-helical, i.e. said
end portions move in preferably the same plane and preferably do
not overlap before, during or after said relative movement has
occurred.
[0011] A said predetermined temperature for end portion closure may
lie in the region of a body temperature of a wearer of said
jewelry. Said shape memory material may exhibit thermal hysteresis
having upper and lower temperature transformation ranges, said
upper temperature transformation comprising a range of 10.degree.
C. or less, preferably 7.degree. C. or less and more preferably
5.degree. C. or less. Said shape memory material may have an upper
transformation start temperature As in the range 18.degree. C. to
23.degree. C. Said shape memory material may have an upper
transformation finish temperature A, in the range 23.degree. C. to
30.degree. C.
[0012] Said shape memory material may comprise a stabilized shape
memory material, trained and adapted for repeated movement between
said open and closed states.
[0013] Removal of said piece of jewelry from a wearer might be
restricted once said jewelry has substantially moved into said
closed state. Said piece of jewelry may be adapted in said closed
state to at least one of partially or fully capture, grip, pass
through or enclose a body part of a said wearer.
[0014] Said relative movement may be adapted to bring said end
portions into engagement, in which state said end portions are in
at least partial abutment with a clamping force therebetween. Said
end portions may comprise a jaw arrangement, preferably
substantially complementary jaws adapted for engagement with each
other.
[0015] One or both said end portions may comprise a locating
arrangement adapted to align said end portions in a substantially
predetermined relationship when said end portions are engaged.
[0016] Said piece of jewelry may further comprise a latching means
adapted to latch said end portions into said closed state at least
temporarily and preferably removably.
[0017] Said piece of jewelry may further comprise an indicator
arrangement adapted to indicate when said end portions are at least
one of open or closed. Said indicator arrangement may comprise
indicia which is at least one of displayed or hidden when said
jewelry is in said closed state.
[0018] Said shape memory section may be adapted to move said end
portions in a substantially pivotal manner.
[0019] Said piece of jewelry may be adapted to be gripped or pulled
on at least a predetermined section and in such a manner that a
gripping or pulling force above a predetermined level moves said
piece of jewelry towards said open state.
[0020] Said end portions may be adapted to be opened from a closed
state under the influence of a said predetermined level of force
applied below a predetermined temperature at which said shape
memory material adopts a pseudo-elastic state. Said temperature may
comprise for example a finish transformation temperature Af for an
austenitic phase of said shape memory material and may be above 0
degrees centigrade, preferably above 10 degrees centigrade and more
preferably between 10 and 30 degrees centigrade.
[0021] Said piece of jewelry may comprise an inactive section,
which may be substantially devoid of shape memory material, such
that said piece of jewelry is adapted to be handled by said
inactive section substantially without changing shape for at least
a predetermined time period, so as for example to enable manual
fittment.
[0022] Said piece of jewelry may comprise an ornamental band whose
said open state comprises a substantially elliptical or enlarged
circular open-ended shape and whose closed state comprises a
reduced gap open-ended shape or a substantially closed shape.
[0023] Said piece of jewelry may comprise a ring whose said open
state comprises a substantially elliptical or enlarged circular
open-ended shape and whose closed state comprises a substantially
closed circle. The ring may comprise a ring adapted to be fitted to
a finger or through a body part such as for example a nose or
ear.
[0024] The present invention also provides an arrangement for
storing and/or fitting a piece of jewelry, said arrangement
comprising a temperature varying device adapted to bring a said
piece of jewelry to or beyond a temperature at which said piece is
moveable into said open state.
[0025] Said temperature varying device may comprise a cooling
chamber adapted to receive a said piece of jewelry and a heat
exchange means adapted to reduce the temperature of said piece in
said chamber.
[0026] Said heat exchange means may comprise an electrically
operated heat sink apparatus, preferably portable and adapted for
battery operation.
[0027] Said heat exchange means may further comprise a biasing
means adapted to bias a ring therein towards said open state.
[0028] The present invention also provides a method of producing a
piece of jewelry, the method including:
[0029] a) providing an elongate piece of material comprising at
least a section which includes a shape memory material;
[0030] b) forming on opposing ends of said piece of material first
and second end portions;
[0031] c) forming said piece of material into an open state adapted
for fittment to a body part of a wearer and in which open state
said end portions substantially face each other spaced apart by a
gap; and
[0032] d) adapting said shape memory material to move said end
portions relative to each other, above a predetermined temperature,
towards a closed state in which said gap is reduced or said end
portions are substantially engaged, whereby shape memory effect is
used for fitting said piece of jewelry to a wearer whilst
simultaneously changing an externally visible shape or
configuration of said piece of jewelry.
[0033] The method may include stabilizing said shape memory portion
for repeated movement of said end portions between said open and
closed states, preferably stabilizing said shape memory material by
training.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIG. 1 shows a schematic illustration of a property change
(such as length) versus temperature for a shape memory element. The
hysteresis, the activation temperature T.sub.A, the deactivation
temperature T.sub.D and the transformation temperatures M.sub.S,
M.sub.f, A.sub.S, A.sub.f are indicated;
[0035] FIG. 2 shows a piece of jewelry according to an embodiment
of the present invention in a first state, shape or
configuration;
[0036] FIG. 3 shows the piece of jewelry of FIG. 2 in a second
state, shape or configuration;
[0037] FIG. 4 is a detailed view of an aspect of the jewelry of
FIGS. 2 and 3;
[0038] FIG. 5 is a side view of a piece of jewelry according to a
further embodiment of the invention; and
[0039] FIG. 6 is a perspective view of a cooling arrangement
suitable for use with embodiments of the present invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0040] The present invention will now be described by way of
example only with reference to certain embodiments and with
reference to the above mentioned drawings.
[0041] Materials, both organic and metallic, capable or possessing
shape memory and/or superelasticity are known. An article made of
materials showing shape memory can be deformed from an original,
heat-stable configuration to a second, heat-unstable configuration.
The article is said to have shape memory for the reason that, upon
the application of the heat alone, it can be caused to revert or
attempt to revert from its heat-unstable configuration to its
original heat-stable configuration, i.e. it "remembers" its
original shape.
[0042] Among metallic alloys, the ability to possess shape memory
is a result of the fact that the alloy undergoes a reversible
transformation from an austenitic state to a martensitic state with
a change of temperature. The transformation from the austenitic
phase to the martensitic phase shows a temperature hysterisis,
illustrated in FIG. 1. It follows that the transformation cannot be
characterized by a single value of temperature, but has to be
characterized by four temperatures: M.sub.S and M.sub.f and A.sub.S
and A.sub.f respectively to indicate the temperatures at which the
martensitic and the reverse martensitic (austenitic)
transformations start and finish. Thus, an article made from such
an alloy is easily deformed from its original configuration to a
new configuration when cooled to a temperature below M.sub.f. When
an article thus deformed is warmed, the deformed object will return
to its original configuration starting at A.sub.s and finishing at
A.sub.f. A shape memory material can thus be formed into a shape
memory element (SME) or article that may be activated and
deactivated between states depending upon temperature.
[0043] Many shape memory alloys (SMA) are known to show also
superelasticity. When an SMA sample exhibiting superelasticity is
stressed at temperature above A.sub.f (so that the austenitic state
is stable), but below M.sub.d (the maximum temperature at which
martensitic formation can occur even under stress) it first deforms
elastically and then, at a critical stress, begins to transform by
the formation of stress-induced martensite. When the stress is
released, the martensite becomes unstable and transforms back to
austenite, with the sample returning to its original shape.
Similarly to the thermally induced transformation, the
stress-induced transformation shows a stress hysterisis.
[0044] In many shape memory alloys, there is a large hysteresis as
the alloy is transformed between austenitic and martensitic states.
Moreover, the transformation ranges, {A.sub.S-A.sub.f} and
{M.sub.S-M.sub.f} can be quite substantial. As a result, reversing
of the state of an SMA element may require a temperature excursion
of several tens of degrees Celsius, or a stress excursion of
several hundreds of MPa. It follows that a temperature excursion of
several tens of degrees (or hundreds of MPa) is required for
activation and deactivation of a device incorporating shape memory
elements. For example, the commercially available near equi-atomic
binary nickel-titanium alloys can have a hysteresis width of about
40.degree. C. The total transformation range {A.sub.f-M.sub.f} can
be easily above 60.degree. C.
[0045] Many applications of shape memory alloys nowadays are using
near equi-atomic binary nickel-titanium alloys. Such
nickel-titanium alloys typically have a hysteresis width of about
40.degree. C. Some prior art proposals for use of shape memory
material in jewelry may be found in DE-19934312 and in EP-0313070,
to which documents the reader is referred for a better
understanding of some current applications.
[0046] An important point for designers of devices using these
materials is that the upper and lower transformation ranges of the
hysteresis curve, {A.sub.s-A.sub.f} and {M.sub.s-M.sub.f}, can be
quite substantial. FIG. 1 shows that in order to switch from the
`on` state at the activation temperature T.sub.a to the `off` state
at the deactivation temperature T.sub.d and vice versa, the
hysteresis and the two transformation ranges have to be overcome.
Large transformation temperature ranges may result in a
slow/sluggish action of such devices or in the need for
unreasonable amounts of force. This may lead to an approach as
proposed in DE-19934312 and in EP-0313070, in which the
transformation ranges of the hysteresis curve, {A.sub.s-A.sub.f}
and {M.sub.s-M.sub.f}, are set such that the jewelry described is
manipulated using only super elastic properties.
[0047] According to the present invention, the shape memory effect
of the material is used as the enabling technology for putting the
jewelry on, i.e. moving it into its in-use or activated state. This
contrasts with the prior art approach of using super elasticity.
Embodiments of jewelry according to the present invention include
ornamental bands that are adapted to be placed and at least
temporarily kept on a body part of a wearer. One embodiment of such
an ornamental band is in the form of a ring is disclosed with
particular reference now also to FIGS. 2 to 4.
[0048] A ring 10 is made in the form of a band 12 including a shape
memory material, the ring 10 having a `cold` shape or configuration
which comprises an open state A in which the ring 10 is adapted to
fit over a finger of a wearer. In the open state A, the ring adopts
a substantially elliptical or enlarged circular state.
[0049] If the ring 10 is formed in such a manner that its active
shape memory material exhibits a two-way shape memory effect, the
ring 10 may be able to adopt the "cold" shape or configuration
purely by shape memory. This will be the case only if the material
is appropriate and if ring 10 is reduced in temperature to a level
at or below the deactivation temperature T.sub.d of that two-way
shape memory material.
[0050] The ring 10 exhibits a super-elastic/pseudo-elastic behavior
at temperatures above A.sub.f. When the ring 10 is opened at such
temperatures, the ring 10 will automatically recover its closed
shape when the force is removed. At temperatures below A.sub.f and
particularly close to or below A.sub.s, however, the ring 10 can be
moved into its open state by applying an appropriate force, e.g. an
outward bias from within the ring 10 or a pulling force from
without. After removal of that force, there will be no or only
partial recovery and the ring 10 remains substantially open. When
fitted, the body temperature of the wearer's finger raises the
temperature of the ring 10 to a temperature above A.sub.f, at which
the ring 10 automatically closes to adopt a "hot" shape or
configuration B in the form of a closed state B having a reduced
diameter compared to the open state A and in which state B the ring
10 encloses the wearer's finger.
[0051] The starting shape memory material used to form the band 12
can have an elongate shape, such as a wire shape, a strip shape and
the like. Opposing ends of the band 12 comprise end portions in the
form of jaws 14, 16 which are mutually opposed in a face-to-face
relationship and are adapted to move substantially into engagement
as the temperature of the ring 10 reaches or exceeds a
predetermined level. Relative movement between the jaws 14, 16 is
adapted to occur in one plane, such that for example the jaws 14,
16 come up against each other in a non-helical fashion and do not
overlap before, during or after relative movement has occurred.
[0052] On closing, the jaws 14, 16 at least partially abut and
exhibit a clamping force therebetween, the force being such that if
the jaws 14, 16 were able to pass each other there would be an
overlap for a typical ring 10 in the hot state B of at least 0.1,
preferably 0.5 and more preferably 1.0 mm, greater levels of
theoretical overlap being possible. The ring 10 may be stabilized
by training the shape memory material to minimize between multiple
cycles residual changes in the hot shape B. The training may
preferably be to such an extent that the residual shape change is
less than the overlap, which enables the ring 10 to be fitted and
removed many times without failing or losing the quality of its
fit. The clamping force grips the opposing ends 14, 16 of the band
12 together such that the ring 10 may appear to a wearer or an
observer to be of continuous construction. This aspect of the
present invention also helps maintain dimensional stability and is
useful in keeping the ring 10 within strict tolerances of finger
sizing.
[0053] Optionally, the jaws 14, 16 may be adapted to carry an
indicator arrangement, which may be in the form of decorative
members such as a pair of name plates 18, 20 representative of two
people getting married. Such plates may comprise, for example gold
name plates and may be fixed to the jaws 14, 16 in a variety of
ways, for example by joining with a fixing means such as an
adhesive, solder, braze, a fusion weld, spot welds, rivet, captive
fixing, clinch or a crimp. Instead of nameplates 18, 20, the
indicator arrangement may comprise names or other marking engraved
directly into the ring 10, e.g. on or to the sides of the jaws 14,
16. The name plates 18, 20 or engraved names would then move
towards each other after an open ring 10 was fitted to the finger
of a wearer and such movement could attract significance to the
couple and observers as part of the ceremony. The nameplates 18, 20
or engraved names further act as indicia of activation and
deactivation of the ring 10, as their abutment is indicative of
closure of the jaws 14, 16. The indicator arrangement may take a
different form and may indeed be reversed, such that for example a
message is visible in the open state A but obscured in the closed
state B. A further version, which may also be combined with another
version, may be to include an item such as a precious stone which
is visible in the open state A and partially or full hidden in the
closed state B. In this manner, perhaps only the wearers would know
such closure indicia were present and the secret could be used to
add significance to the giving ceremony.
[0054] The jaws 14, 16 may in a simple form be no more than
opposing faces at the ends of the band 12 but are preferably at
least formed or worked so as to make a close fit, i.e. a join which
will be substantially imperceptible to a wearer or observer and
have no visible or feelable gaps. The jaws 14, 16 may optionally
include a locating arrangement adapted to bring the opposing jaws
14, 16 into substantial alignment by self-centering them as they
come into engagement and abutment. One exemplary version of such a
locating arrangement is illustrated in FIG. 4 and comprises a male
dowel 14a on one jaw 14 which is adapted to enter a substantially
corresponding cavity 16a defined in its opposing jaw 16,
self-centering being achieved by chamfers 14b, 16b of the dowel 14a
and the cavity 16a respectively. The locating arrangement may in
addition comprise a latching means, which can add further
mechanical strength to the clamping force of the jaws 14, 16 and
may help in cases where the ring 10 makes excursions into cold
regions and may get caught and pulled open. Such a latching
arrangement may also take on a symbolic significance to a couple
getting wed, although it should preferably be reversible in case
the ring 10 needs to be removed, e.g. in the case of injury.
[0055] Once fitted, the ring 10 can be removed from the digit of a
wearer reasonably easily but hardly accidentally, any optional
latching means permitting. This will, however, usually call for a
deliberate decision to do so and the appropriate course of action
being followed. For example, removal may be effected by cooling the
ring 10 in a saline solution chilled with blocks of ice and by
pulling it open using manual force or a mechanical aid such as a
gripping or expanding device. Such a mechanical aid may comprise a
pincer device adapted to partially flatten at least a portion of
the circumference of band 12, or may be in the form of an adapter
that can be used with conventional pliers. This device or adapter
may be the same device used to move the ring 10 into its open state
A for initial supply.
[0056] Clearly, the A.sub.f point should be selected so that the
temperature of such a saline solution is not unreasonable for a
wearer. The A.sub.f point should not, however, be too high for two
reasons. Firstly, if the A.sub.f point becomes too close to body
temperature, the closing action may be too slow which could be
undesirable or even impractical, e.g. during a wedding ceremony.
Secondly, the A.sub.f point should not be too high as that might
make the ring 10 moveable towards its open state A at too high a
temperature. For these reasons, an A, point of above 30 degrees
centigrade may prove too high. For comfort, an A.sub.f point above
zero degrees centigrade is however preferred, more preferably above
10 degrees centigrade and most preferably between 10 and 30 degrees
centigrade. In this manner, a ring 10 can be delivered in an open
state A, from which it will move into a closed state B when
fitted.
[0057] Optionally, the ring 10 may not comprise a complete band of
shape memory material and may only comprise a section thereof in
the form of a predetermined activation portion 12a of the material.
Such an arrangement may position the activation portion 12a at the
bottom of the band 12, so that it is best positioned to cause equal
relative movement between the jaws 14, e.g. by pivoting the jaws 14
towards each other and into engagement. This option also allows for
one or more inactive sections 12b substantially devoid of shape
memory material, by which the ring 10 can be held with an increased
time to activation, such as might prove useful for a giver of the
ring during a ceremony.
[0058] In any case, end portion closure simultaneously achieves
jewelry fitting and reaches an in-use aesthetic appearance by
changing an externally visible shape or configuration of the
jewelry in response to a temperature change.
[0059] Delivery of a ring 10 according to the invention should be
carefully controlled, in order to prevent it from closing and
potentially causing embarrassment at for example a wedding service.
The ring 10 may be placed in its open state A by cooling
sufficiently below M.sub.s (if it exhibits two-way shape memory
effects), or more preferably by mechanically forcing it open at a
temperature at or below A.sub.f. In cases of mechanical forcing,
temperatures sufficiently below A.sub.f are preferred, since this
reduces the chances of damaging the ring 10.
[0060] As discussed above, the force may be applied using a
mechanical aid to partially deform a portion of the band 12, which
may be the active section 12a. Once opened, it is important to keep
the ring 10 in this state A and to this end a temperature varying
device 100 may be provided with particular reference for the moment
to FIG. 6.
[0061] The temperature varying device 100 comprises a chamber 102
which is adapted to receive the ring 10 and may be associated with
an electrically operated cooling circuit 104 powered by batteries
for portability (not shown separately). Forms of cooling other than
electrically based arrangements may be used, e.g. self-chilling
CO.sub.2 modules. The cooling chamber 102 keeps the ring 10 at or
below a temperature between about 0 and 20 degrees centigrade, such
that it is cool enough once removed to stay open for long enough to
fit it during a ceremony.
[0062] For practical purposes, it is preferable that the
temperature varying device 100 is non-intrusive and this may lead
to a requirement for a small internal battery pack. In order to
keep power consumption down, in a variation to this fitting
arrangement, the ring 10 may be placed in the chamber in a closed
state B and the temperature varying device 100 transported switched
off and the ring 10 therefore substantially at ambient
temperature.
[0063] For aesthetic purposes, it may be desirable to disguise the
temperature varying device 100 in a presentation box (not shown).
The temperature varying device 100 and presentation box may be
loaned or hired in returnable fashion, e.g. when the ring 10 is
supplied or for its transport and/or storage in relation to a
ring-giving ceremony.
[0064] Once near the ceremony, the temperature varying device 100
is switched on and cools the ring 10 to a temperature at or below
A.sub.f, e.g. between about 0 and 20 degrees centigrade. It will be
apparent, however, that in order to supply the ring 10 in an open
state A at the ceremony, means must be provided to move it into the
open state A once below A.sub.f. This could be achieved by opening
the box and applying manual or aided force, as discussed above, and
then replacing the ring 10 in the box. This could cause
embarrassment if forgotten and it is preferable to deliver the ring
10 open or to provide opening means adapted to open the ring 10
automatically and without user intervention, yet still keeping down
battery power consumption. This may be achieved, for example, by
using a biasing means adapted to apply a pulling or pushing force
from respectively outside or inside the ring 10. The bias applied
should be sufficient to open the ring 10 automatically once the
temperature varying device 100 has been switched on and cooled the
ring 10 to or below a predetermined temperature, dictated by the
properties of the ring 10 and the biasing device employed.
[0065] A simple version of biasing means might be an elastomeric
insert that is squeezed into a closed ring 10. Another approach
would be to provide pulling or pushing arms 106, 108 which are
integrated into the temperature varying device 100 and may usefully
be biased to apply an opening force on the ring 10 through means of
a biasing element such as a spring (not illustrated separately).
Such a biasing element would preferably be hidden from view and the
arms 106, 108 may be retractable, e.g. on accessing the ring 10, so
as to enhance the aesthetic appeal of the presentation.
[0066] A simple and alternative method would be to pre-open the
ring 10 at or below A.sub.f and to jig it in the open position,
e.g. by inserting a dowel or by placing it over a solid former in
the cooling chamber. Such an approach is, however, less desirable
than the biasing means discussed above.
[0067] Other embodiments of ornamental bands according to the
jewelry of the present invention may include bracelets, earrings,
body piercings and necklaces. These bands can be opened when
subjected to a low temperature to ease fitting around, to or
through the respective body part and then close automatically when
they are heated by body warmth of the wearer.
[0068] Like all embodiments of the present invention, there is a
change in externally visible shape or configuration of the jewelry
that occurs simultaneously with fitting, i.e. from a first state
adapted for fitting to an in-use state. This change in external
shape or configuration can be used to achieve one or both of
functional or aesthetic goals.
[0069] Such bands may have one or more of the features now
discussed, many of which may be common with features relating also
to finger rings 10 according to the first embodiment of ornamental
band discussed above. The band (which might be integrated in
another element) may be fitted nicely around, over, through or
gripping against a body part, without any additional swinging
hinges, manually actuated locks, screws and the like. The band will
close or expand at high temperatures and can be opened or shrunk at
lower temperatures. The band's shape or configuration may be
changed or varied with temperature differences.
[0070] Referring now for the moment in particular to FIG. 5, in
accordance with the present invention a bracelet is made in the
form of a band 60 and includes a portion of shape memory material.
The band 60 comprises a substantially rigid structure in the form
of an open bangle formed from a starting material comprising a
strip, bar or wire bent around into a substantially circular or
elliptical non-overlapping band shape. It will be appreciated that
other shapes such as polygons may be formed. A pair of end portions
in the form of substantially complementary spherical pieces 62, 64
are formed at the opposing ends of the band 60 and face each other
across a gap once the material has been bent, e.g. around a
former.
[0071] The shape memory material is adapted to give the band 60 a
closed state, which comprises a `hot` shape or configuration B, and
an open state which comprises a `cold` shape or configuration A. In
the cold shape A, the band is in a substantially elliptical or
enlarged circular open-ended shape A in which the spherical pieces
62, 64 are spaced apart by a gap 66 large enough to allow the band
60 to be fitted to a body part of a wearer, e.g. a wrist. In the
hot shape B, the band 60 adopts a closed shape B which comprises a
substantially elliptical or circular shape B having an inter-piece
gap 66' reduced from the gap 66 of the cold shape A, and thus
possibly restricting removal of the band 60 from the body part. The
gap 66, 66' between the spherical pieces 62, 64 therefore reduces
during transitions from the cold shape A to the hot shape B and
increases during transitions from the hot shape B to the cold shape
A, thus simultaneously achieving jewelry fitting/removal and
reaching/leaving in use aesthetic appearance by changing an
externally visible shape or configuration. In common with each
embodiment of the present invention, the piece of jewelry is
non-helical and its end portions move relative to each other in a
substantially face-to-face relationship and preferably in
substantially the same plane.
[0072] When it comes to fitting (or removing) the band 60, if not
already open A, the band 60 can be deformed below a predetermined
temperature, e.g. by hand and into the `cold` shape A. Cooling may
be performed using for example a saline solution, iced (or possibly
just cold) water, a freezing spray or equivalents.
[0073] Thus, fitting to a wearer is performed by putting the band
into its open state A and then heating the band 20 so that it
adopts the closed state B. Heating is performed by for example body
temperature, whereupon the band 20 will move from the cold shape A
to the hot shape B automatically. It can thus be seen that, in
similar fashion to the finger rings 10 discussed above, shape
memory effect is used as the mechanism to fit/remove the jewelry,
i.e. to move the end portions into/out of an in-use or as-worn
condition B, while simultaneously changing an externally visible
shape or configuration. The shape memory material is preferably
stabilized by training, such that fitting and removal can be
repeated as often as desired.
[0074] The shape memory material may comprise a metal alloy and the
processing of the shape memory base material is performed in order
to have transformation temperatures A.sub.S, A.sub.F, M.sub.S and
M.sub.F in the necessary range. In a preferred embodiment, the
bracelet 60 can be opened at lower temperatures and keeps the open
shape at temperatures at or slightly above room temperature. In
this way the bracelet 60 with the open shape A can be stored and
transported easily. The corresponding technical request is that
A.sub.S and A.sub.F should be sufficiently high. It will be
appreciated that a cooling apparatus and/or a jigging arrangement
similar to that described above may be adapted for such bracelets
60 and other bands.
[0075] The larger the temperature difference between body
temperature and A.sub.F, the faster will be the shape change from
the cold shape A to the hot shape B. A sufficiently fast action is
required for practical and aesthetic reasons and it follows that
A.sub.F has to be sufficiently below body temperature. For
practical reasons, it should be possible to open the bracelet at
sufficiently high temperatures, for which it follows that A.sub.S
should be sufficiently high.
[0076] Combining the requests above, it also follows that a small
temperature range for the reverse transformation is preferred, for
aesthetic reasons as well as for practical reasons. As an example,
an A.sub.S close to 22.degree. C. (between 18.degree. C. and
25.degree. C.) and an A.sub.F close to 28.degree. C. (between
23.degree. C. and 30.degree. C.) is preferred. The difference
between A.sub.F and A.sub.s is preferably 10.degree. C. or less,
more preferably 7.degree. C. or less and most preferably 5.degree.
C. or less. The reason for this is that such a bracelet can be
opened at some degrees centigrade below A.sub.S. Hence, A.sub.S
should not be too low otherwise a low temperature will have to be
applied which may be inconvenient for the wearer. The same or
similar considerations apply to material suitable for the
production of jewelry according other embodiments of the present
invention, such as the closing ring 10 discussed above.
[0077] The shape memory material for many embodiments of jewelry
according to the present invention can be made of many shape memory
materials.
[0078] Some Examples:
[0079] binary Nickel Titanium (abbreviated to Ni--Ti);
[0080] Nickel Titanium with other alloying elements;
[0081] Nickel Titanium Copper with other alloying elements;
[0082] Nickel Titanium Copper Chromium;
[0083] Cu based shape memory alloys, such as CuZnAI and CuAINi with
further
[0084] alloying elements; and
[0085] Au based shape memory alloys.
[0086] The transformation temperatures of most shape memory alloys
are composition and processing dependent. In order to obtain the
appropriate transformation temperatures, alloys of appropriate
composition and which underwent appropriate processing have to be
selected.
[0087] With regard to production of the jewelry, the starting
material may be wire, strip and the like with correct dimensions
and made of appropriate alloys which have undergone appropriate
processing (see above). The further production of the bands can
involve several steps, such as (i) shape setting treatments, (ii)
extra heat treatments, (iii) polishing and coloring processes, and
(iv) adding other objects. The sequence given here is only
indicative; other sequences can be followed.
[0088] Considering shape or configuration setting treatment, in
this step the hot shape B is given to the shape memory element. It
typically involves (i) the production of a mandrel with the
appropriate shape, (ii) fixing the shape memory element on or
around the mandrel, (iii) putting the mandrel with the fixed shape
memory element in a furnace or the like (molten salt bath or
similar) for appropriate times and at appropriate temperatures, and
(iv) cooling and removing the shape memory element from the
mandrel. Afterwards, the shape memory element will have the
required hot shape. Taking the example of Ni--Ti based elements,
the heat treatment temperature and time will be typically
400-550.degree. C. for 2 to 30 minutes, although other procedures
can be followed. Additional heat treatments might be required to
shift the transformation temperatures or to change the ductility of
the shape memory elements.
[0089] For aesthetic reasons, polishing and coloring treatments
might be required. Grinding and polishing (electropolishing or
mechanical polishing) will give a metal color. For the case of
Ni--Ti based elements, yellow, blue, black and intermediate surface
colors can be obtained by appropriate heat treatment. Different
colors can also be obtained via coatings and paints.
[0090] Other objects can be connected to the shape memory elements.
For example for the case of the bracelet, diamonds, golden balls
and the like can be put on the shape memory element for aesthetic
reasons.
[0091] While the present invention has been particularly shown and
described with respect to a preferred embodiment, it will be
understood by those skilled in the art that changes in form and
detail may be made without departing from the scope and spirit of
the invention.
* * * * *