Note: Descriptions are shown in the official language in which they were submitted.
- BACKGROUND OF THE INVENTION
This invention relates to personal thermal devices~and
particularly to personal heating and cooling apparatus of the
types wherein a temperature controlling fluid is circulated
through a thin, flexible heat exchange structure. Such thermal
devices have been~~known and used for many years in a variety
of applications, Generally, these devices have rc~omp~ hoses
or similar articles arranged in various patterns throughout a
pad or matrix of some design which may or may not have been
covered with a cloth material. Some devices have employed
single passageways in various configurations and other devices
have employed multiple passageways in order to provide a large
heat transferning area within a given sized pad or blanket. All
of these prior art devices have suffered from a particular
problem which has generally been called "pinch off". The
problem of pinch off manifests itself when a thermal pad or
blanket has one of the fluid passages kinked or otherwise
obstructed so that the flow of fluid therefhrough is prevented.
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When this occurs the function of the device is immediately
destroyed. It has been proposed in the past to use a hard,
- pinch off resistant material for the fluid passage; however,
when such a material is used it becomes difficult to bend the
pad or it becomes uncomfortable for a patient or user who is
employing the pad.
It would, therefore, be an advance in the art if a thermal
device of this nature could be provided which obviated or greatly
reduced the problems associated with pinch off. Prior art pads
or thermal devices have also been troubled by a wide temperature
variances across the pad, caused primarily by the elongated,
serpentine configurations of the fluid passages. These long
passages, with their continuous welds, also made the pads less
flexible than desired and made them difficult to wrap about a
limb.
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Prior art devices of this type have al~o had the problem
of not being capable of being folded. Folding immediately
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cuased a pinch-off condition. Therefore, it would be a further
. advance in the art if a pad were provided which could be folded
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- 20 many different ways and still maintàin fluid flow.
O JECTS AND~SUMMARY OF THE INVENTION
It is, therefore, an object of the invention to obviate
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the disadvantages of the prior art.
It is another object of the invention to enhance the
operation of thermal devices.
Yet another object of the invention is the provision of a
thermal device that is almost impossible to pinch off.
Yet another object of the invention is the provision of a
thermal device that can be folded to smaller sizes and still
maintain fluid flow in the smaller size.
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Still another object of t~e ~ invention is the
provision of a thermal device that has a very small temperature
difference between various areas of the device,
Another object of the invention is the provision of
a thermal device that conforms easily to uneven body contours.
These objects are accomplished in one aspect of the
invention by the provision of a thermal device for providing area
heating or cooling by means of continuous fluid flow comprising
a flexible pad formed from two overlying sheets of fluid
impervious material peripherally sealed to form a fluid tight
compartment; fluid inlet means and fluid outlet means communica-
ting with said compartment, said inlet means and said outlet
means being closely adjacent; and a plurality of fluid directing
passages formed within said compartment, said passages being
defined by a large plurality of discontinuous sealed areas having
a given space therebetween, said sealed areas being discontinuous
in all directions and defining a multiplicity of alternate flow
~ paths for said fluid.
- BRIEF DESCRIPTION OF THE DRAWINGS
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Fig. 1 is a plan view of one embodiment of the
invention;
Fig. 2 is a perspective view of a pad folded in half;
Fig. 3 is a perspective view of a pad folded in
quarters; and
Fig. 4 is an elevational view of an alternate hose
termination;
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Figs. 5-7 are additional views of alternate
embodiments of hose terminations; and
Fig. 8 is a plan view of the embodiment of Fig. 4.
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DESCRIPTION ~F THE PREFERRE~ EMBODIMENTS
For a better understanding of the present invention,
together with other and further objects, advantages, and capa-
bilities thereof, reference is made to the following disclosure
and appended claims taken in conjunction with the above-described
drawings.
Referring now to the drawings with greater particularity
there is shown in Fig. 1 a thermal device 10 for providing area
heating or cooling to a mammalian body or limb thereof. Device
10 comprises a flexible pad formed from two overlying sheets 12
and 14 of fluid impervious material such as sheet vinyl. The
sheets 12 and 14 are provided with a peripheral seal 16 to form
a fluid tight compartment 18. Fluid inlet means 20 and fluid
outlet means 22 in the form of hoses 20a and 22a, respectively,
are provided in one section of the device 10 and communicate at
one end thereof with compartment 18. The other ends thereof are
connected, respectively, to a fluid source and a fluid drain,
`-~. not shown.
A plurality of fluid carrying passages 24 are provided within
compartment 18, these passages being defined by a large plurality
of oriented, discontinuous sealed areas 26 having a given space,
designated as A, therebetween. In the instant embodiment of
Fig. 1, the sealed areas 26 are circular in configuration, this
shape providing strength as well as even fluid flow thereabout;
however, it is to be understood that other geometric shapes can
be employed, such as squares, rectangles, bars, ovals, etc.
When the material is vinyl, the sealed areas and peripheral seal
can be formed by dielectric welding.
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In the preferred embodiment, at least one of the fluid
directing passages is formed to provide a fluid inlet passage 24a
and at least one other of the fluid directing passages is formed
to provide a fluid outlet passage 24b. The passages 24a and 24b
are separated from the remainder of the passages by oriented,
discontinuous sealed areas 26a and 26b, which areas have a
spacing B therebetween which is less than A. As an aid to venti~
lation, some or all of the seal areas 26, 26a and 26b can be
provided with apertures 27 therethrough.
The serpentine arrows overlying the passages 24, 24a, and
24b in Fig. l indicate the normal direction of fluid flow there_
through. It can clearly be seen from viewing this Fig. l that
a pinch-off between any two or more areas 26 will have virtually
no effect upon the fluid flow, since such a restricted area will
simply be bypassed.
A further advantage of this construction is illustrated in
Figs. 2 and 3 which show, respectively, a device lO folded in half
and a device lO folded in quarters. In each of these conditions
the available section of the device lO which communicates with
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the inlet and outlet means 20 and 22, continues to function
normally.
The pattern of the sealed areas 26 which form the main body
of device lO is capable of many variations: e.g., the pattern in
Fig. l is a linear, square design having sealed areas at the
corners of a square with alternate rows being offset by l/2 square.
Hexagonal patterns are also appropriate as are non-linear patterns.
The particular pattern employed will determine the direction of
fluid flow.
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The peripheral seal 16 also performs a function in aiding
fluid flow, and is preferably provided with rounded corners.
A further area where pinch-off has always been a problem
is that area immediately adjacent the point where the fluid inlet
and outlet means join the interior of the compartment 18. This
condition is effectively reduced or eliminated by insuring that
hoses 20a and 22a terminate within compartment 18 in a
discontinuous plane. This can be accomplished as shown in Fig. 1
by extending one of the hoses further into compartment 18 than
10 the other. Alternatively, the discontinuous plane can be
provided at the terminal end of the hose.
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~ In Fig. 4 the terminal end of inlet hose 20a is provided
- with a single V notch 28.
In Fig. 5 the end is provided with multiple, elongated V
notches 30; in Fig. 6 perforations 32 are provided; and in Fig.
~ 7 a single diagonal cut 34 Fig. 8 is a plan view of the hose
- of Fig. 4.
When formed with either of these therminations a discontin_
` uous plane exists within compartment 18, thereby making it
extremely difficult for a pinch-off to occur in this area,
It will be seen from the above description ~hat a new and
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~ novel thermal device is created. The device has many advantages
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over the prior art, namely- it can be folded and still function;
it is virtually impossible to pinch off; it is simple and
economical to fabricate; and it can be covered and used to
; dispense medicaments or be moistened for wet heat applications.
The lack of continuous welded serpentine passages makes the
device more flexible when fluid filled and allows ready conformance
with uneven body areas.
Further, tests with water of about 105F have shown less
than about 3F to 4F temperature variation between various
parts of the device.
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While there has been shown and described what are at present
cons;dered to be the preferred embodiments of the preferred
: embodiments of the invention, it will be obvious to those skilled
;~ in the art that various changes and modifications may be made
therein without departing from the scope of the invention as
defined by the appended claims.
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