US2991627A - Thermoelectric blanket - Google Patents

Description

July 11, 1961 c. G. SUITS THERMOELECTRIC BLANKET 2 Sheets-Sheet 1 Filed July 1, 1959 inventor: Chauncey G. Su/i's, b Ma. 0% /-//'s Attorney.

July 11, 1961 c. G. SUITS 2,991,627

THERMOELECTRIC BLANKET Filed July 1, 1959 2 Sheets-Sheet 2 Jnventor': Chauncey G. Suits,

by M4 32 His Attorney.

United States Patent 2,991,627 THERMOELECTRIC BLANKET Chauncey G. Suits, Schenectady, N.Y., assignor to General Electric Company, a corporation of New York Filed July 1, 1959, Ser. No. 824,281 8 Claims. (Cl. 62-3) This invention relates to a thermal device and more particularly to a cooling and heating blanket which may be placed in close proximity to an object, such as a human body, for removing excess heat therefrom.

The comforting and therapeutic effects of maintaining the human body in an environment of a prescribed range of temperatures are Well known and considerable effort has been directed toward the provision of means to accomplish this end. In particular, the advantages to be derived by removing excess body heat during sleeping hours are well know Hereto-fore, proper cooling of sleeping environs such as a room or an entire building has been provided by suitable air conditioning apparatus involving refrigeration machinery or simply large air circulating fans. Installations of these types are large, bulky and expensive in initial cost, as well as being difiicult and expensive to operate and maintain.

Alternate schemes for providing cooling of a human body during sleep have included thermal blankets utilizing the circulation of a liquid coolant through suitable flexible tubes embedded therein. These, however, have disadvantages in that they are heavy and require complex, inconvenient and often expensive auxiliary apparatus. Moreover such previous blankets present serious safety hazards and destruction of blanket and bedding from leaks that may occur in cooling tubes.

It is, therefore, a principal object of my invention to facilitate the cooling of objects, particularly of the human body during periods of inactivity by the provision of a cooling blanket obviating the use of cooling tubes containing a circulating cooling liquid or other complicated auxiliary equipment.

It is another object of my invention to facilitate cooling of the human body, particularly during sleep, without the necessity of cooling at least an entire room.

It is still another object of my invention to facilitate controlled cooling of the human body particularly during sleep, by simple and inexpensive means.

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which I regard as my invention, the invention will be better understood from the following description taken in connection with the accompanying drawings in which:

FIGURE 1 illustrates in perspective view, partially cut away, an entire blanket according to my invention, together with heat removing means and control apparatus therefor,

FIGURE 2 shows in detail a single Peltier junction unit and the circuitry necessary for forming a component of the cooling apparatus of the invention,

FIGURE 3 is a detailed view in perspective showing the arrangement of cooling apparatus components forming part of the blanket shown in FIGURE 1,

FIGURE 4 is an enlarged cross-sectional elevation, the details of construction of the blanket in FIGURE 1 and in particular showing the details of a modified arrangement of Peltier unit interconnections adjacent to air passages therein,

FIGURE 5 is an enlarged, cut-away perspective view, illustrating in greater detail, the arrangement of difierent parts of the blanket as a whole, and

FIGURE 6 illustrates in perspective another embodiment of the invention showing the construction and interconnection of cooling units of the blanket.

In accordance with my invention, I avoid the aforementioned disadvantages of prior cooling apparatus by the provision of a cooling blanket in which is disposeda plurality of Peltier junctions through which direct electrical current is passed to obtain cooling. The portion of each junction in which cooling occurs is disposed on a side of the blanket which isplaced adjacent to the body and the portions of the Peltier junction in which heat is generated are disposed on the side of the blanket remote from the cool side and are exposed to either ambient air or to confined regions through which ambient air is circulated by force, to increase the removal of heat from the hot junction. The combined effects of the many Peltier junctions is to provide a large continuous area on one side of the blanket which is cooled and which may absorb excess body heat while the combined heat dissipating portions of the Peltier junctions together with the circulation of ambient air thereover, facilitates the complete removal of such excess heat from the other side of the blanket. To provide flexibility in all planes to the blanket, the portions of the Peltier material are conductively joined by flexible metal straps which may, for example, be woven wire. Although the blanket of my invention finds its greatest utility in its cooling function it is also within the purview of my invention to reverse the effect of the Peltier junctions to produce heat by the blanket to warm objects adjacent thereto as the occasion may require.

Referring now more particularly to FIGURE 1 of the drawings, 10 represents generally the entire blanket of my invention which includes a pair of opposed portions 12 and 14 which may be of a suitable cloth material interiorly rubberized as at 15 and joined together at one end by a selvage 16 and at the other end being rounded and folded back at 18 to form a pocket 29 with connecting sides as at 22, conformable with one end of a mattress to form a contour-type blanket.

As shown in FIGURES 4 and 5 of the drawings as well as in FIGURE 1, between the cloth portions 12 and 14 there is disposed a layer of flexible material 24 having electrical and thermal insulating properties and may, for example, be foam rubber. A plurality of spaced grooves such as 21 and 23 are formed along the length of the material 24 for accommodating a like plurality of rows of Peltier cooling junctions as shown at 26 and 28. The rows of cooling junctions are embedded in the material 24 and one side of each junction unit is adjacent to the cloth 12 on the one side of the blanket. The grooves are separated by walls of the material 24, as shown at 25 and 27 in FIGURES 4 and 5, and the number of such rows is such as to provide substantial coverage of the entire area of the blanket. Thus, a groove is near each portion of the side 12 of the blanket.

As shown more clearly in FIGURE 2 of the drawings showing a representative Peltier junction unit and its electrical circuit, each Peltier junction includes a pair of members as at B0 and 32, of Peltier material joined at one end by a conductive member as at 34. As an alternative embodiment of my invention, the members may be in direct contact with each other without the use of a member as 34, care being taken to provide a surface of sufficient contact area between members, as an example, one or both of these members may be of L-shape such that the portion of the unit comprising the member 34 in FIGURE 2, could be a part of either of the Peltier members or portions of this connecting member may be integrally formed and be of respective Peltier materials. One of the members of Peltier material of each junction is of p-type semiconducting material and the other is of n-type semiconducting material. In the circuit of the Peltier junctions, a direct potential, as represented by battery 36, is applied across the ends of the Peltier materials remote from the joining member 34. In accordance with the well known Peltier effect, when the potential of the p-type member is positive with respect to the potential of the n-type member, causing a current flow through the junctions, a heat transfer occurs in the Peltier materials whereby the ends joined with member 34 are cooled with respect to their initial temperature and the ends remote from these junctions are heated. Many materials suitable as Peltier materials 30 and 32 are known and they may, for example, be p-type and n-type bismuth telluride, respectively.

The extent of cooling produced at each junction is affected by the length of the Peltier members, with greater lengths, less than a predetermined value at which maximum effect is achieved, producing greater cooling. In accordance with my invention, the Peltier members are of a length at which efiective cooling is produced and may be divergent away from each other as shown in the drawings to establish wide grooves in which disposed, the unoccupied portions of which provide channels enlarged in width for circulating a fluid coolant.

The potential required to be applied between the ends of the Peltier members is determined by the lengths of the Peltier members and the extent of cooling desired. Under the circumstances herein, wherein blanket thicknesses of the order of A1 inch are contemplated, the potential difierence across each Peltier junction unit may be a few volts as, for example, 2 volts. Thus, for use with the conventional power supply in the usual dwelling, viz., a 115 volts, 60 cycle supply, with a suitable rectifier, the rows of Peltier junctions in the blanket 1t comprise groups of junction units connected in series circuit arrangement as shown in FIGURE 3, for example. A suflicient number of such units are so connected to reduce the potential difference across each unit to a value at which such unit is usefully operable. As shown in FIGURE 3, the Peltier junction unit 37 is connected in series with the next adjacent unit 38- by a connector bar 40 and the next adjacent unit 41 by a bar 42, etc. These connector bars may be rigid; however, for imparting flexibility to the blanket, flexible conductive straps, as shown at 44 and 46 in FIG- URE 3, may be substituted at spaced locations for certain of the rigid bars. In accordance with another embodiment of my invention, as shown in FIGURE 6, even further flexibility may be imparted to the blanket by providing flexible, conductive straps for each series connection between Peltier junction units.

For supplying electrical current to the Peltier junction units, a rectifier, preferably of a well-known dry type such as a selenium type, not shown, may be provided and contained in the housing of an electrically driven blower 48. An electrical cord and plug 50 facilitates connection to the usual house current supply for operating the Peltier junctions and a suitable rheostat 52 with control knob 53 may be coupled to the supply source for controlling the current flow in the junctions and therefore, for controlling the extent of cooling.

As hereinabove explained, the ends of the Peltier materials remote from the connecting member are raised in temperature during operation of the blanket. For dissipating the heat so produced, air channels as at 54 and 56 are established adjacent to such ends and one cloth side, 14, of the blanket as shown in FIGURE 4 of the drawings. Each channel is further confined by walls of insulating material 24 between the grooves. Each air channel above each row of junctions is in communication With each adjacent air channel at its respective ends, thus forming a continuous air path through the blanket above the rows of junctions. To enhance the cooling of the heated portions of each junction, ambient air is circulated through the air path so formed, by blower 48, which discharges air through a flexible tube 55 into an intermediate point of the continuous air path described. Such air is divided and follows two paths of substantially equal length through the air channels and is discharged at respective ports 57 and 58 at opposite sides of the blanket and near one end thereof. For controlling the rate of such air flow, the motor of blower 48 may be provided with a suitable rheostat controller, operated by a knob 60.

In accordance with another feature of a modification of my invention, as shown in FIGURE 4 of the drawing, the bars interconnecting the Peltier units may be made wider than the semiconducting members with which they interconnect so as to overhang as shown at 62, for example. With such construction, the heat dissipating area of the units is increased to improve the effectiveness and efliciency of the blanket.

While the present invention has been described by reference to particular embodiments thereof, it will be understood that numerous modifications may be made by those skilled in the art without actually departing from the invention. 1, therefore, aim in the appended claims to cover all such equivalent variations as come within the true spirit and scope of the foregoing disclosure.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A thermal blanket comprising a pair of spaced layers of cloth material and a layer of flexible non-conductive, foam rubber therebetween, said foam rubber having a plurality of grooves therein separated by ridges of said foam rubber and a plurality of Peltier junction units in each groove, each unit including a member of p-type semiconducting material and a member of n-type semiconducting material and means adjacent a first side of said blanket establishing conductive contact between said semiconducting materials of each unit, means serially connecting the Peltier units in each groove and including a flexible strap conductively connected between the p-type member of one unit and the n-type member of the next adjacent unit in one direction, means serially connecting the pluralities of Peltier junction units in the several rows with p-type members conductively joined to n-type members in the respective grooves, means establishing an electron current from the n-type member to the p-type member in each unit, the height of said units being less than the depth of said grooves to form a passage between said units and the second of said cloths and means for circulating ambient air through said passage to absorb and remove heat from the portions of said uni-ts remote from said first side whereby cooling of said first side of said blanket occurs.

2. A thermal blanket comprising: a pair of spaced layers of cloth material; a layer of flexible material having electrical and thermal insulating properties disposed between said cloth layers; a plurality of Peltier junction units distributed in and supported by said layer of flexible material each Peltier junction unit including a member of P-type conductivity semiconductive material, a member of N-type conductivity semiconductive material and a conductive joining member in contact with an end of each of said semiconductive members and being adjacent a first one of said cloth layers; flexible air passage means enclosing the ends of said P-type and N-type members remote from said joining member; means controllably establishing a flow of electron current from the N-type member of one Peltier junction to the P-type member of an adjacent Peltier junction unit said means further providing freedom of movement therebetween in all planes; and means for circulating ambient air through said flexible air passage means.

3. A thermal blanket comprising: a pair of spaced layers of cloth material; a layer of flexible material having electrical and thermal insulating properties disposed between said cloth layers; a plurality of Peltier junction units distributed in and supported by said layer of flexible material, each Peltier junction unit including a member of P-type conductivity semiconductive material, a member of N-type conductivity semiconductive material and an electrically conductive member joining one end of each of said P-type and N-type members; flexible air passage means integral with said layer of flexible material for enclosing the ends of said semiconductor members remote from said joining member; means controllably establishing a flow of electron current from each N-type member of one Peltier junction unit to the P-type member of an adjacent unit said means further providing freedom of movement therebetween in all planes; and means for circulating ambient air through said flexible air passage means to absorb and remove heat from the ends of said junction units enclosed therein.

4. A thermal'blanket comprising: a pair of spaced layers of cloth material; a layer of flexible material having electrical and thermal insulating properties disposed between said cloth layers; a plurality of Peltier junction units distributed in and supported by said layer of flexible material, each Peltier junction unit including a member of P-type semicondnctive material, a member of N- type semiconductive material and a conductive joining member in contact with an end of each said semiconductor member and adjacent a first one of said cloth layers; flexible air passage means enclosing the ends of said semiconductor members remote from said joining members, said air passage means being enclosed on two sides by portions of said flexible material and on the top by the other of said cloth layers; means for controllably establishing a flow of electron current from the N-type member of one Peltier junction unit to the P-type member of an adjacent unit, said means including flexible connecting means to provide freedom of movement between said Peltier junction units in all planes; and means for circulating ambient air through said flexible air passage means.

5. A thermal blanket comprising: a pair of spaced layers of cloth material; a layer of flexible material having electrical and thermal insulating properties disposed between said cloth layers; a plurality of Peltier junction units distributed in and supported by said layer of flexible material, each Peltier junction unit including a member of P-type semiconductive material, a member of N- type semicondnctive material and a conductive joining member in contact with an end of each semiconductor member and adjacent a first one of said cloth layers; a plurality of flexible air passage means enclosing the ends of said semiconductor members remote from said joining members, each of said air passages being confined on two sides by walls of said flexible material, on top by the other of said cloth layers and in communication with each adjacent air passage at its respective ends; means for connecting the end of each except one N-type member remote from said joining member to an end of a P-type member remote from said joining member otherwise unconnected, said means providing electrical conduction between said semiconductor members and freedom of movement therebetween in all planes; means for applying a direct current potential across the unconnected ends of said semiconductor members establishing current flow through said units in series; and means for circulating ambient air through said plurality of air passage means to absorb and remove heat from the ends of said semiconductor members enclosed therein.

6. A thermal blanket comprising: a pair of spaced layers of cloth material; a layer of flexible material having electrical and thermal insulating properties disposed between said layers of cloth material, said flexible material having a plurality of grooves therein separated by ridges of said flexible material; a plurality of Peltier junction units disposed in each groove, each unit including a member of P-type semicondnctive material, a member of N- type semicondnctive material and means adjacent a first side of said blanket establishing electrical contact between said P-type and said N-type member, the height of said units being less than the depth of said grooves to form a passage between said units and the second of said cloth layers; means serially connecting the Peltier units in each groove and including a flexible strap electrically connected between the P-type member of one unit and the N-type member of the next adjacent unit in one direction; means serially connecting the pluralities of Peltier junction units in the several grooves with P-type members conductively joined to N-type members in the respective grooves; means establishing an electron current from the N-type member to the P-type member in each unit; and means for circulating ambient air through the passage formed between said units and the second of said cloth layers to absorb and remove heat from the portions of said units remote from said first side whereby cooling of said first side of said blanket occurs.

7. A thermal blanket comprising: a pair of spaced layers of cloth material; a layer of flexible material having electrical and thermal insulating properties disposed between said layers of cloth material, said flexible material having a plurality of channels therein confined by walls of said flexible material and in communication with each adjacent channel at its respective ends; a plurality of Peltier junction units disposed in each of said channels each including a member of P-type semiconductive material, a member of N-type semicondnctive material and means adjacent a first cloth layer establishing electrical contact between an end of said P-type member and an end of said N-type member, said semicondnctive members being divergent away from each other on the respective ends remote from said contact; means controllably establishing a flow of electron current through each of said Peltier junction units from the N-type member to the P- type member, said means including flexible connecting means to provide freedom of movement therebetween in all planes; and means for circulating ambient air through said plurality of channels for removing heat from the diverging ends of said semiconductor members adjacent said second cloth layer.

8. A thermal blanket comprising: a pair of spaced layers of interiorly rubberized cloth material; a layer of flexible material having electrical and thermal insulating properties disposed between said layers of cloth material, said flexible material having a plurality of grooves therein separated by ridges of said flexible material; a plurality of Peltier junction units in each groove each including a member of P-type semicondnctive material and a member of N-type semicondnctive material in electrical contact with each other, the height of said units being less than the depth of said grooves to form a passage between said units and one of said layers of cloth material; means serially connecting the Peltier junction units in each groove and including a flexible strap electrically connected between the P-type member of one unit and the N-type member of the next adjacent unit in one direction; means for establishing an electron current through each Peltier junction unit from the N-type member to the P-type member; and means for circulating ambient air through said passage formed between said Peltier junction units and said one of said cloth layers to remove heat from the ends of said semiconductor members adjacent said passage.

References Cited in the file of this patent UNITED STATES PATENTS 413,136 Dewey Oct. 15, 1889 2,110,022 Kliesrath Mar. 1, 1938 2,504,308 Donkle Apr. 18, 1950 2,749,716 Lindenblad June 12, 1956 2,870,610 Lindenblad Jan. 27, 1959 2,93 8,356 McMahon May 31, 1960

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