[0001] The present invention relates to domestic equipment primarily for use in performing
laundry tasks such as pressing and ironing clothing, but which is also adaptable for
other uses. Although it has long been recognised in commercial laundries that pressing
of clothes can most effectively and quickly be performed by means of apparatus which
applies heat to both sides of the fabric, this fact has not in the main been taken
into account in the domestic laundry. Pressing or ironing tasks are almost always
performed in a domestic situation by applying a heated flat iron to the upper surface
of garments supported on an unheated platform in the form of an ironing board or table.
[0002] Although previous attempts have been made to produce a heated ironing board or table
these have not been technically entirely satisfactory and for this reason have not
met with significant commercial success. For example, the prior art heated ironing
boards have either been unable to provide a sufficiently high temperature to obtain
a significant effect or, if the temperature was sufficiently high, there were inadequate
safeguards to prevent the user from becoming burned or at least made severely uncomfortable
by the heat given off by the board. Thus, although domestic ironing is considered
by many as a tedious and time consuming chore, and although various attempts have
been made to automate the processes concerned in order to reduce the time involved,
the majority of people still iron clothes using only a flat iron and an unheated ironing
board or table. Apparatus previously tried in an attempt to speed up the process includes
heated rollers between which the domestic items are intended to be passed in order
to effect pressing thereof. Such equipment has failed to gain general acceptability
however because the rather complex shapes of garments of wearing apparel cannot satisfactorily
be accommodated by such a roller arrangement.
[0003] By way of example of another prior proposal, FR-A 2128966 describes a sleeve-board
with a heatable surface having a series of holes or ducts for the passage of steam,
and an articulated pressure plate attached thereto at one end of the said heatable
surface.
[0004] The present invention seeks, therefore, to provide an improved apparatus capable
of enabling domestic ironing or pressing operations to be performed more quickly and
easily than has hithertofore been possible, whilst at the same time providing comfort
and security for the user.
[0005] According to one aspect of the present invention, there is provided domestic laundry
equipment comprising a heatable ironing board having a substantially flat working
platform, platform support means for supporting the working platform spaced from the
ground, a heater for raising the temperature of the platform surface, and a pressure
plate for cooperation with the heatable platform to form a static press assembly for
pressing garments such as trousers, characterised in that means are provided for detachably
connecting the pressure plate to the heatable platform.
[0006] The present invention preferably includes a working platform in the form of an ironing
board or table having an electrical resistance element associated therewith for generating
heat to raise the temperature of the surface of the platform of table to a value in
the region of 90°C to 120°C. The electrical resistance element may be provided in
one of a number of different ways. For example, the electrical resistance element
may be embedded in the material of the platform, which for this purpose may be a suitable
ceramic or plastics insulating material, or may be of metal with suitable ceramic
or plastics insulators, or insulators of other suitable material between the metal
and the electrical resistance elements, or may be aluminium or other material having
high thermal conductivity.
[0007] Alternatively the electrical resistance element may be carried by a cover which overlies
the surface of the platform. Such a cover may be formed as a separate laminar sheet
or as a sleeve which can be held in position on the platform by suitable means such
as tie straps or press studs, or by bolt ropes engaged in cooperation grooves in the
board or table. It is preferred that there are provided means for connecting the said
electrical control circuit to the platform electrical heater whereby the said electrical
control circuit exercises simultaneous independent temperature control of said flat
iron and the said heatable platform by regulating the electrical supply thereto.
[0008] In a preferred embodiment the electrical control circuit means comprises an energy
regulator, means for connecting the said energy regulator to a source of electrical
supply and means for connecting said energy regulator to the said electrical resistance
heater of the said platform.
[0009] Means may be provided to detect the temperature of the surface of the working platform.
Such means may comprise one or more sensors, and this temperature detection can be
used to control the energy supplied to the resistance element. The temperature sensors
may be of a conventional bi-metal strip type or may be thermocouples.
[0010] The present invention therefore provides apparatus by means of which a domestic ironing
board may be used as a trouser press by cooperatively adapting it with a pressure
plate and means for heating the trousers or other garment pressed between the board
and the plate. The ironing board is heated but optionally the pressure plate may additionally
be provided with heater means, in which case both the pressure plate and the ironing
board platform have heaters, whereby garments are pressed by heat applied to both
sides simultaneously.
[0011] In another aspect the present invention provides a heated ironing board having end
portions which fold under the platform to reduce the length of the ironing board and
allow it to be used as a food warming hot plate.
[0012] The control circuit on the board may include a timer which automatically switches
off the resistance heating element of the platform after a predetermined period of
time. This allows the user to set up the static press assembly comprising the board
and the pressure plate, and leave the equipment in operation to attend to other matters.
Means are provided for resiliently urging the pressure plate firmly into contact with
the platform. For convenience the support frame or legs of the ironing board may be
adapted with a spacer stay so as to hold the platform in a generally upright orientation
with one end in contact with the ground where in normal operation the support frame
holds the platform generally horizontally.
[0013] According to further optional features of the invention, the said electrical platform
heater comprises two separate heater elements extending over different areas of said
platform, the said platform being formed in two parts substantially co-extensive with
said two heater elements respectively, one said platform part being foldable with
respect to the other said platform part between a first position where it lies substantially
coplanar with said other platform part and a second position where it is folded to
a position out of the plane of said second platform part. Coupling means may be provided
on the said plate for mounting the latter to the said platform of the ironing board,
the said coupling means including resilient biasing means for urging the said plate
into contact with the said platform under pressure when said plate means is mounted
thereon, and heater means on the said pressure-applying plate.
[0014] A resilient foam cover means may be provided for said working platform to cover the
hard upper surface thereof and provide a resilient flexible surface suitable for pressing
or ironing garments by means of the flat iron, and quick release attachment means
for securing said resilient foam cover means in position over the said working platform
whilst allowing ready removal thereof to expose the said hard upper surface for use
as a food-warming platform or other heating uses.
[0015] Various embodiments of the present invention will noe be more particularly described,
by way of example, with reference to the accompanying drawings, in which:-
Figure 1 is a perspective view of a first embodiment of the invention shown in its
normal operating position;
Figure 2 is a perspective view of the embodiment of Figure 1 adapted for use as a
trouser press;
Figure 3 is a sehcmetic circuit diagram of the electrical circuit for controlling
the energy supplied to the resistance heater element of the embodiment illustrated
in Figures 1 and 2;
Figure 4 is a circuit diagram of a control circuit suitable for use in an embodiment
of the present invention;
Figure 5 is a perspective view of a second embodiment of the invention, illustrated
in its fully erected position;
Figure 6 is a perspective view of the embodiment of Figure 5, shown in a partly collapsed
position;
Figure 7 is a perspective view of the embodiment of Figure 5 in a fully collapsed
position and with a cooperating pressure plate fitted thereto;
Figure 8 is an exploded view of some of the components of the embodiment of Figure
5; and
Figure 9 is a cross-sectional view taken on the line IX-IX of Figure 7.
[0016] Referring now to the drawings, the embodiment shown in Figure 1 is externally very
similarly formed to a conventional ironing board and is generally indicated with
the reference number 11. The ironing board 11 com prises a generally planar approximately
rectangular platform 12, tapered at one end, and carried by an underlying support
frame generally indicated 13 and comprising two legs 14, 15 pivotally connected at
a point intermediate therein by a pivot 16, and each having a transverse foot 17
for engaging the ground when the board 11 is erected for use. Suitable means for inter-engaging
the support frame legs 14, 15 with the underside of the platform 12 to effect variation
in the height of the platform above the ground are provided, but such may be conventional
and are not described in further detail herein.
[0017] A platform 12 is provided with a resistance heater element 18, made from an insulated
electrical element embedded in the material of the platform 12 and connected to a
power supply panel generally indicated 19 carried at one end of the platform 12. The
power supply 19 has an electrical lead 20 terminating in a conventional plug 21 for
connection to a mains wall socket of normal type. The platform 12 may be constituted
by one or a plurality of elements or units of a ceramic or glass material with heating
elements embedded in them, or alternatively may be any other suitable, perfectly electrical
insulating material having a high thermal conductivity capable of withstanding continuous
use of the high temperatures involved in operation. Such temperatures may be, for
example, in the region of 90°C to 120°C and may reach even higher values locally,
for example in the immediate vicinity of the heater elements. A cover element of material
having thermal insulating properties to meet the criteria discussed below in relation
to the embodi ments of Figures 5 to 9 is also employed but is not illustrated in
Figure 1.
[0018] On one side of the power supply panel 19, namely the side facing the observer in
Figure 1, there is provided a socket 23 for receiving a cooperating plug of an electrical
lead of a pressing iron to be described in more detail below. A changeover switch
22 and an isolating switch 24 are also provided for purposes which will be described
in more detail below, and an indicating lamp 25 is provided, which lamp illuminates
when the apparatus is plugged in.
[0019] As can be seen from Figure 3 the electrical lead 20 is applied via a fuse 26 to a
circuit junction 27 in a lead 29 with the lamp 25 being connected directly across
between the positive and neutral terminals of the lead 20 to provide an indication
at all times that the apparatus is plugged in. A timer 28 is connected between the
lead 29 and a lead 30 which is connected to an energy regulator 31 which is connected
via a second lead 32 to the neutral wire 33 of the lead 20, and via a lead 34, to
the switch 24, which latter is connected in series with the electrical resistance
element 18 of the platform 12. A line 38 leads from a junction point 39 in the line
30, between the timer 28 and the energy regulator 31, to a terminal 40 of the switch
22 which also has a contact 42 in the line 34 between the energy regulator 31 and
the switch 24 and a contact 43 constituting the moyable contact of the changeover
switch 22. The movable contact 43 is connected to a line 44 leading to one contact
pin of the socket 23 the other contact pin of which is connected to the neutral line
33.
[0020] An electrical iron having a resistance heating element but no temperature control
mechanism can be provided for use with the ironing board of the present invention.
Such an iron is connected to the socket 23 by means of a suitable cooperating plug
with which can be provided, and the combined energy consumption of the resistance
heating element of the iron, taken via the socket 23, and the electrical resistance
element 18 of the ironing board 12 is controlled by the energy regulator 31 which
can be suitably set by a control knob 36 on the power supply control panel 19.
[0021] By opening the switch 24 the electrical resistance element 18 can be disconnected
leaving the power supply extending only through the socket 23 to the iron enabling
greater control of the equipment when handling delicate fabrics such as silk. By commuting
the changeover switch 22 to the oppsite position from that shown in Figure 3 the energy
regulator is cut out of the supply to the socket 23. An electric iron having its own
thermostat can then be used either along or in combination with the energy regulated
heated platform 12.
For use as a trouser press the support frame 13 is provided with a lug 40 and stay
41 so that the platform 12 can be positioned in a generally upright orientation. Between
the platform 12 and the power supply control panel 19 is a hook-shape channel 42 which
receives one end of a flat pressure plate 44 having a pair of spring loaded connector
arms 45 with hooked ends for interconnection with cooperating catches 46 on the platform
12. When suitably positioned on the platform 12 the pressure plate 44 can be used
to apply pressure for example to a pair of trousers which can be introduced between
the pressure plate 43 and the platform 12, the pressure being maintained by the springs
47 of the connector arms 45. When a pair of trousers has been positioned between
the pressure plate 44 and the platform 12 the equipment is switched on and it automatically
switches off after a predetermined time set by the timer 28. Although not illustrated,
the pressure plate 44 may be provided with its own heater element and a lead which
can be plugged into the mains or the socket 23 so that heat can be applied to both
sides of a pair of trousers at once. Likewise the trouser press, although shown in
operation in a vertical position, may alternatively be used in a horizontal position
for such items as pleated skirts, curtains or like such items. The present invention
also comprehends trouser pressing apparatus comprising an electrically heated pressure
plate adapted to be attached by pressure-applying means to a conventional unheated
ironing board and to be plugged directly into the mains supply.
[0022] In the second embodiment of the invention illustrated in Figures 5 to 9, there are
provided resistance heater elements which can be used after removal of a protective
cover to provide a firm surface and a higher temperature so that the apparatus can
serve double duty as a food hotplate to maintain food at the right temperature after
cooking. This can be controlled by means of a suitable rotary switch and indicated
by an additional light or lamp. Operation of such a switch would also disconnect the
outlet socket 23 for safety reasons.
[0023] When the apparatus is used as a food hotplate the trouser press plate, with its own
fabric cover removed (if it has one), can be used as a cold shelf by fitting it to
supports under the platform 12, in a manner which will be described in more detail
with reference to Figures 5 to 7 below.
[0024] First, however, the circuit of Figure 4 will be described. This circuit is provided
for control of a special flat iron (not shown) and is intended to be mounted on the
board of Figures 1 to 3 or on the board of Figures 5 to 9 and to control the specially
adapted flat iron connected thereto via a socket such as the socket 23 of Figure 1
but which would be formed as a five pin socket instead of the three pin socket shown
in Figure 1. Such a socket is connected to form electrical leads 48, 49, 50 51 and
to a safety earth wire (not shown). The leads 50, 51 are in use connected via this
socket to wires leading to a thermistor in the iron and the leads 48, 49 are in use
connected via the socket to wires leading to the resistance element of the iron.
[0025] In operation the circuit is supplied from a source connected to terminals 58,59.
Across these input terminals are connected the contacts 60 of a relay the coil 61
of which is connected across the terminals 58, 59 with a protection resistor 62 in
series therewith and the collector-emitter jumction of a transistor 63 controlling
the energisation of the relay coil. The transistor 63 forms part of a Darlington pair
with a second transistor 64 the base of which is connected between two resistors 65,
66 in a voltage dividing circuit arrangement at the output of an amplifier 67 connected
to a differential summing amplifier, the non-inverting input of which receives signals
from a bridge circuit comprising the thermistor which is connected across lines 50,
51 and is in series with a resistor 68 between the positive voltage line 69 connected
to the input terminal 58 and the negative line 70 connected to the input terminal
59. The other arm of the bridge comprises resistors 71 and 72 connected between the
positive line 69 and the negative line 70 and the junction between which is connected
via a resistor 73 to the inverting input of the amplifier 67. The resistor 72 is a
variable resistor the adjustment of which determines the selected temperature of operation
of the system. The circuit also includes a capacitor 75 the function of which will
be described below.
[0026] The operation of the circuit is as follows. Depending on the selected resistance
of the resistor 72 the temperature variation experienced by the thermistor in the
flat iron once the heating element in the iron is energised will change the balance
conditions of the bridge comprising the thermistor itself, the resistor 71, the resistor
68, and the resistor 72 which are connected, as described above, in pairs across the
non-inverting and inverting inputs of the amplifier 67. As the temperature experienced
by the thermistor due to the heating effect of the elements 55 and 51 (the iron will
of course be applied to the board during use with the item being ironed being located
between the boards and the iron) the resistance of the thermistor falls until the
bridge passes a balance point allowing the capacitor 75 to discharge through the thermistor
causing a surge in the current which is ampli fied by the differential amplifier
67 applying a control signal to the base of the transistor 64 causing it, and therefore
the transistor 63, to conduct completing the circuit through the coil 61, energising
it and thereby opening the normally closed contacts of the relay 60. Power is thus
cut off to the heater element connected across lines 50, 51 and this then starts to
cool until the resistance of the thermistor has increased to such a value as to cause
the bridge to become unbalanced again stopping the amplifier 67 from conducting and
thereby switching off the transistors 64, 63 de-energising the coil 61 and allowing
the contacts 60 to reclose and allow current to pass again to the heating element
which therefore again starts to heat up.
[0027] Turning now to the embodiment illustrated in Figures 5 to 9, the ironing board comprises
a platform having a main portion 76 and an end portion 77 hingedly connected thereto
so as to be turnable between an erected position illustrated in Figure 5 and a folded
position illustrated in Figure 6. At the opposite end of the main platform portion
76 is a control panel 78 which is also hingedly mounted to the main portion 76 by
means of a piano-type hinge 79 so that it can turn between an erected or extended
position as illustrated in Figure 5 and a folded position as illustrated in Figure
6. Suitable spring clips or other retaining means 80 are provided for retaining the
control box 78 in its extended position and likewise, suitable retaining means (not
illustrated) are provided for holding the end portion 77 of the platform in its extended
position so that it remains substantially coplanar with the main portion 76 when pressure
as applied from above in use of the ironing board.
[0028] The platform comprising the main panel portion 76 and the end portion 77, together
with the control box 78 is supported on two pairs of legs identified as a near pair
81 adjacent the control box 78 and a distal pair 82 nearer the far end of the panel
76. The distal legs 82 are spaced closer together than the near legs 81 and all the
legs are pivotally mounted to the underside of the panel 76 so that they can be folded
to a collapsed position or to a partly collapsed position as illustrated in Figure
7.
[0029] The legs 81, 82 are provided with retaining means (not shown) for supporting a subsidiary
shelf 83 which, as can be seen in Figure 7, can be fitted to the main panel portion
76 of the platform in a suitable manner to act as a trouser press pressure plate like
the pressure plate 44 in the embodiment of Figures 1 to 3.
[0030] Referring now to Figure 7 the platform 76 comprises a supporting base 84 to one end
of which the control box 78 is hingedly mounted by the piano hinge 79 (Figure 6) whilst
at the other end a distal support panel 85 is correspondingly hinged by a suitable
piano hinge (not shown). The electrical resistance element is formed in two parts
86, 87 each of which respectively overlies the support platform 84 and distal portion
85 to which they are secured by a heat distribution cover panel, again formed in two
parts 88, 89.
[0031] The material used for the heat distribution cover panel 88, 89, is preferably a light
metal such as aluminium or an aluminium alloy or other material having a high thermal
conductivity. The operating surface temperature range envisaged for the surface of
the board is between 90°C and 120°C, which gives faster and better ironing results
when used with a domestic pressing iron having a temperature lying in the range of
120° to 210°C. It is envisaged that the temperature control of the ironing board surface
will be adapted to the temperature control of a domestic pressing iron such that a
temperature of 90°C at the board surface will be provided with an iron temperature
of 120°C and, at the other end of the range, an ironing board surface temperature
of approximately 120°C will be matched by an iron temperature of about 210°C. Corresponding
adjustments, which may be incremental or infinitely variable, may be provided by
the temperature control mechanism.
[0032] The board operating temperatures are achieved by employing electrical resistance
elements 86, 87 having the appropriate electrical resistance to give an electrical
loading in the region of 0.4 Watts per cm². A typical surface area for a traditional
ironing board surface is in the region of 2250 cm² and at 0.4 Watts per cm² the total
electrical loading would thus be 900 Watts. The heat-up time of an electrical element
having these parameters will match that of a currently available domestic pressing
iron so that the heated board will be ready for use at the same time as the pressing
iron assuming that both are switched on at the same time.
[0033] The 900 Watts electrical load, when considered in combination with the 1100 Watt
electrical load of a currently available dry/steam iron gives a total electrical consumption
of 2 Kw, but because the ironing time is reduced by at least 33⅓% the overall electrical
energy consumption is in many cases less than that consumed with an unheated board
over the longer time period taken to complete the pressing and ironing operations.
[0034] The heat distribution elements 88, 89 shown in Figure 8 are aluminium with elongate
fixing holes 90 allowing for firm clamping to the platform parts 86, 78 by rivets,
screws or the like whilst still allowing longitudinal expansion to take place upon
heating. The element 88 is provided with retaining legs 91 (either by attachment or
by cutting out a suitable peripheral shape) for attaching the element 88 to the platform
86. By fixing these legs 91 to the platform 76 at a position spaced from their junction
with the heat distribution element 88 separate means for accomodating later expansion
of the plate are rendered unnecessary. Narrow slots 92 across the periphery from
one edge to a position near to but not reaching the opposite edge are additionally
provided to accommodate longitudinal expansion of the heat distribution plate 88 if
this is considered necessary, but even this expansion can be accommodated by the resilience
of the legs 91 with a suitable structure. The important feature is that the plate
88 should be freely movable over the underlying support to allow expansion and contraction
with the increase and decrease in temperature during use and storage without being
restrained in a manner likely to cause buckling or bowing.
[0035] The electrical resistance element is formed in two pairs, 86, 87 with the element
87 being approximately one third of the total area of the ironing board surface. A
microswitch 101 (Figure 7) is provided to disconnect the resistance element 87 from
the control box 78 and thus from the supply of electricity when the end portion 77
is folded for example for use with the pressure plate 93 as a trouser press. An electrical
switch (not shown) in series with the resistance heater element 87 may alternatively
or additionally be provided, which can be mechanically actuated by a cooperating
member on the trouser press pressure plate 83 so that when this pressure plate is
fitted to the board the electrical connection to the element 87 is broken even if
it is not folded to the position illustrated in Figure 6.
[0036] The electrical resistance element 86, 87 comprise electrical resistance wires encased
in mica, but may be made of other material such as lead/tin foil elements encapsulated
in Mylar plastics film which has a temperature resistance of up to 130-150°C. In alternative
embodiments electrical resistance wires may be embedded directly with suitable insulation)
into the material of the heat distribution element 88.
[0037] Heat resistant insulated leads 89 extend from the surface of the board to the control
box 78 which also serves as an iron rest.
[0038] As illustrated in the cross-sectional view (Figure 9) a cover 96 for the board has
a flexible bolt rope 104 attached to the longitudinal periphery of the cover 96, which
latter comprises two layers 102, 103 of fabric encasing a reticulated foam 94. The
platform 84, 85 has an edge groove 95 into which the bolt rope 104 is introduced to
slide the cover 96 onto the board and retain it firmly under tension. The upper surface
layer 102 of the cover 96 is made from thin high quality tightly woven cotton or like
material whilst the under side has a looser more open weave. Longitudinal tension
is maintained by attaching the bolt rope 104 to resilient fasteners or springs 97
fixed to one end of the platform 76.
[0039] One end of the cover 96 may be left open so that the foam element 94 may be withdrawn
for replacement of the cover if this should become damaged or worn with long use whilst
retaining the foam element 94. This latter may be a reticulated polyethylene or like
foam which is silicon treated by a vulcanization technique to make it resilient to
high temperatures.
[0040] In another embodiment (not illustrated) the foam material layer 94 is directly secured
to the heat distribution plate 88 by means of suitable heat resistant adhesive, the
whole then being covered with a single layer of fabric as a cover.
[0041] Finally, the distal legs 82 are provided with folding hooked feet 98 which can be
used when the ironing board is folded as illustrated in Figure 7 to engage in suitable
sockets 99 of a wall plate 100 which serves as a mounting bracket allowing the ironing
board to be suspended from a wall in a tidy space saving manner.
1. Domestic laundry equipment comprising a heatable ironing board (11) having a substantially
flat working platform (12; 76, 77), platform support means (14, 15, 17) for supporting
the working platform (12; 76, 77) spaced from the ground, a heater (18; 86, 87) for
raising the temperature of the platform surface, and a pressure plate (44; 83) for
cooperation with the heatable platform (12; 76, 77) to form a static press assembly
for pressing garments such as trousers, characterised in that means (42, 45, 47) are
provided for detachably connecting the pressure plate (44; 83) to the heatable platform
(12; 76).
2. Domestic laundry equipment according to Claim 1, characterised in that the pressure
plate (44; 83) includes a separate heater element whereby to apply heat to both sides
of a garment simultaneously.
3. Domestic laundry equipment according to Claim 1 or Claim 2, characterised in that
the said connecting means (42, 45, 47) comprise mechanical connecting members (45)
carried on the said pressure plate (44) for engagement with cooperating members (46)
on the ironing board platform, resilient biasing means (47) acting between the said
pressure plate and the connecting members whereby to urge the said pressure plate
(44) into contact under pressure with the platform (12) of the ironing board when
the connecting members (45) are engaged with said cooperating members (46).
4. Domestic laundry equipment according to any of Claims 1 to 3, characterised in
that the said platform support means comprise a plurality of legs (81, 82) and the
said pressure plate (83) is provided with engagement means at or adjacent the edges
thereof for cooperative engagement with mounting means carried by the said legs so
that the plate (83) can be carried beneath the platform (76) to serve as an additional
shelf when it is not being used as a garment press.