US3796100A - Element having bimetal properties - Google Patents

Element having bimetal properties Download PDF

Info

Publication number
US3796100A
US3796100A US00266351A US3796100DA US3796100A US 3796100 A US3796100 A US 3796100A US 00266351 A US00266351 A US 00266351A US 3796100D A US3796100D A US 3796100DA US 3796100 A US3796100 A US 3796100A
Authority
US
United States
Prior art keywords
fibers
group
thermal expansion
matrix material
coefficient
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00266351A
Inventor
F Schneider
D Stockel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
RAU FA G
Original Assignee
RAU FA G
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from DE19712136171 external-priority patent/DE2136171C3/en
Application filed by RAU FA G filed Critical RAU FA G
Application granted granted Critical
Publication of US3796100A publication Critical patent/US3796100A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K5/00—Measuring temperature based on the expansion or contraction of a material
    • G01K5/48—Measuring temperature based on the expansion or contraction of a material the material being a solid
    • G01K5/56—Measuring temperature based on the expansion or contraction of a material the material being a solid constrained so that expansion or contraction causes a deformation of the solid
    • G01K5/62—Measuring temperature based on the expansion or contraction of a material the material being a solid constrained so that expansion or contraction causes a deformation of the solid the solid body being formed of compounded strips or plates, e.g. bimetallic strip
    • G01K5/64—Details of the compounds system
    • G01K5/66—Selection of composition of the components of the system
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12014—All metal or with adjacent metals having metal particles
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12014—All metal or with adjacent metals having metal particles
    • Y10T428/12028—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, etc.]
    • Y10T428/12063—Nonparticulate metal component

Definitions

  • the subject of this invention is an element having bimetal properties and made of a composite fiber material comprising a matrix material and at least one group of fibers embedded therein.
  • the bimetal properties may be achieved by using a matrix material having a coefficient of thermal expansion differing from that of at least one group of embedded fibers.
  • the coefficients of thermal expansion of at least two groups of embedded fibers may differ from each other to achieve such properties.
  • Yet another possibility is to combine these two methods to achieve the desired bimetal properties.
  • the invention relates to an element having bimetal properties which can be used in palce of the known bimetal elements for temperature-dependent regulation or control functions or for the indication of temperature.
  • Bimetal elements are known in a very wide variety of forms for use in indicating temperature and in initiating control operations in dependence upon temperature. These bimetal elements consist of at least two different inseparably connected layers of metal or non-metallic material having different coefficients of thermal expansion. Since, when heated, one of the layers expands to a greater extent than the other, bimetallic elements of this kind bend on a change of temperature, the extent of bending being dependent upon the difference in the coefficients of thermal expansion of the material of the individual layers.
  • Bimetallic elements can be used in either of two ways: their free unrestricted deflection, dependent upon temperature, may be used such as in bimetal spiral thermometers, or thermal power may be produced by largely completely suppressing the deflection of the element such power doing mechanical work and displacing regulating elements (e.g. bimetal ignition means in gas-heated equipment).
  • their free unrestricted deflection, dependent upon temperature may be used such as in bimetal spiral thermometers, or thermal power may be produced by largely completely suppressing the deflection of the element such power doing mechanical work and displacing regulating elements (e.g. bimetal ignition means in gas-heated equipment).
  • bimetallic elements mainly consist of materials having different coefficients of thermal expansion secured together by welding, soldering, bonding and the like.
  • the known bimetallic elements do not fulfil all the important practical requirements.
  • a particular disadvantage resides in the fact that with relatively broad bimetal strips the isotropy of the thermal expansion results in a very undesirable transverse curvature in addition to the required longitudinal bending, and this transverse curvature leads to mechanical stiffening of the strip. In this way, the required deflection is partly inhibited.
  • the choice of material is primarily determined by the thermal properties of the connected layers. This of necessity means that disadvantageous properties as regards electrical conductivity, corrosion-resistance etc., have to be accepted.
  • An object of the present invention is to eliminate the above-stated disadvantages and to provide a bimetal element which possesses particularly advantageous properties.
  • the invention is mainly characterized in that the element is made of a composite fiber material comprising at least one metallic component.
  • Composite fiber materials of this kind contain randomly or specifically distributed fibers embedded in a matrix material, and in a preferred form, both the matrix material and the fibers are made of metallic materials.
  • the composite fiber material can be produced by known metallurigcal methods, based for example on powder metallurgy, but it is advantageously produced by jointly coldshaping the matrix and fiber materials.
  • the term composite fiber material is not, however, intended to be limited exclusively to purely metallic combinations in the present case, since for specific uses composite fiber materials of which the matrix or fiber material is nonmetallic, e.g. plastics material, can be produced.
  • the composite fiber material comprises a first component constituted by a matrix material and a second component constituted by at least one group of fibers embedded in the matrix material
  • the coefficients of thermal expansion of at least two groups of fibers embedded in the matrix material of the composite fiber material differ from each other, or if a matrix material is selected that has a coefficient of thermal expansion differing from that of at least one group of fibers embedded in the matrix material.
  • the matrix material can be freely selected to meet particular additional requirements, namely, corrosion-resistance, specific weight, electrical and thermal conductivity, good mechanical deformability etc.
  • the fibers can be selected not only with the required coefficients of thermal expansion in mind, but also with a view to obtaining the necessary mechanical properties, electrical resistance, magnetic properties and so on.
  • Use may also be made of combinations of materials as normally employed in the known bimetal elements.
  • a considerable advantage of the element of the invention resides in the fact that the matrix material may be selected largely independently of the choice of the fiber that result in deflection of the element under the effect of heat.
  • elements made of a composite fiber material do not become rigid, due to the isotropy of the thermal expansion, as do the known elements in the form of strips.
  • the elements of the invention provide large deflections and large return forces.
  • the entire cross-sectional area of a group of fibers having a low coefficient of thermal expansion may be greater than the entire cross-sectional area of a group of fibers having a higher coefficient of thermal expansion, since generally the selected matrix material reinforces the expansion of the group of fibers having the higher coefficient.
  • Groups of fibers can be distributed in the matrix ma terial in various ways and in accordance with the required defiectional movement.
  • the groups of fibers can be arranged in parallel layers; this arrangement appears to be particularly suitable in the case of elements in the form of strips.
  • the use of the composite fiber material offers the possibility of making a torsional bimetal element in the form of a strip, this being achieved by arranging a group or groups of fibers over the crosssection of the matrix material in such a way that a temperature-responsive torsional moment results.
  • an asymmetric distribution of the groups of fibers in an element in the form of a strip is expedient, so that corresponding torsional moments can be obtained.
  • a further important improvement may be achieved by embedding, in the element, insulated fibers for electrical heating purposes and/or for conducting current.
  • thermoelectric, directly heatable control element By incorporating heating fibers or by appropriately selecting the fibers forming the fiber material, e.g., using the known nickel-iron alloys, which exhibit advantageous coefficients of thermal expansion as well as good electrical resistance properties, a thermoelectric, directly heatable control element can be formed in a simple manner.
  • the elements may be produced with a wide variety of cross-sectional forms having cornered and circular contours. Also, the dimensions of the elements can be suited to meet particular requirements.
  • FIG. 1 is a perspective view of a sectioned element in which groups of fibers are distributed in parallel layers;
  • FIG. 2 shows an element having torsional properties
  • FIG. 3 shows an element in which there are groups of fibers having different cross-sectional dimensions.
  • FIG. 1 shows an element in the form of a strip and made of metallic matrix material 1 in which are embedded a first group 3 of metallic fibers having a low coefficient of thermal expansion and a second group 2 of metallic fibers having a higher coefficient of thermal expansion.
  • the strip acquires a convex upward curvature.
  • the group of f1- bers 3 having the lower coefficient of thermal expansion is asymmetrically arranged in relation to the group 2 having the higher coefficient of thermal expansion so as to produce a torsional moment.
  • the strip 1 of matrix material twists about its longitudinal axis, so that direct rotary movements can be initiated in a particularly advantageous manner.
  • the matrix material 1 is so selected that it reinforces the expansion of the second group 2 of fibers having the higher coefficient of thermal expansion, and it will be seen that the crosssectional distribution of the fibers of group 3 differs from that of the fibers of group 2.
  • insulated resistance-heating wires 4 are embedded between the two groups of fibers so that the strip-like element can be directly heated.
  • a first component comprising a matrix material and having imbedded therein at least one additional component, each of said at least one additional components comprising a group of fibers;
  • one of said components having a coefficient of thermal expansion different from that of at least another of said components.
  • said at least one additional component comprises a single group of fibers, and wherein said matrix material has a coefficient of thermal expansion different from that of said single group of fibers.
  • said at least one additional component comprises second and third additional components, each of said second and third components comprising a group of fibers.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Laminated Bodies (AREA)

Abstract

The subject of this invention is an element having bimetal properties and made of a composite fiber material comprising a matrix material and at least one group of fibers embedded therein. The bimetal properties may be achieved by using a matrix material having a coefficient of thermal expansion differing from that of at least one group of embedded fibers. Alternatively, the coefficients of thermal expansion of at least two groups of embedded fibers may differ from each other to achieve such properties. Yet another possibility is to combine these two methods to achieve the desired bimetal properties.

Description

United States Patent Schneider et al.
ELEMENT HAVING BIMETAL PROPERTIES Inventors: Friedrich Schneider; Dieter Stockel,
both of Pforzheim, Germany Assignee: G. Rau, Pforzheim, Germany Filed: June 26, 1972 Appl. No.: 266,351
Foreign Application Priority Data July 20, 1971 Germany 2136171 US. Cl. 73/3635 Int. Cl. G01k 5/62 Field of Search 73/3635, 363, 363.1;
References Cited UNITED STATES PATENTS 12/1927 Steel 29/195.5
3,107,532 10/1963 Lingnau ..73/363.5
Primary Examiner-Donald O. Woodiel Attorney, Agent, or FirmWenderoth, Lind & Ponack [5 7] ABSTRACT The subject of this invention is an element having bimetal properties and made of a composite fiber material comprising a matrix material and at least one group of fibers embedded therein. The bimetal properties may be achieved by using a matrix material having a coefficient of thermal expansion differing from that of at least one group of embedded fibers. Alternatively, the coefficients of thermal expansion of at least two groups of embedded fibers may differ from each other to achieve such properties. Yet another possibility is to combine these two methods to achieve the desired bimetal properties.
10 Claims, 3 Drawing Figures PATENTEDHAR 12 I974 3. 796. 1 0O oooooooooodooq O06 O00 5 7.2 j
o 0 0 o 0L0 o o 0 0p 0 ELEMENT HAVING BIMETAL PROPERTIES BACKGROUND OF THE INVENTION The invention relates to an element having bimetal properties which can be used in palce of the known bimetal elements for temperature-dependent regulation or control functions or for the indication of temperature.
Bimetal elements are known in a very wide variety of forms for use in indicating temperature and in initiating control operations in dependence upon temperature. These bimetal elements consist of at least two different inseparably connected layers of metal or non-metallic material having different coefficients of thermal expansion. Since, when heated, one of the layers expands to a greater extent than the other, bimetallic elements of this kind bend on a change of temperature, the extent of bending being dependent upon the difference in the coefficients of thermal expansion of the material of the individual layers.
Bimetallic elements can be used in either of two ways: their free unrestricted deflection, dependent upon temperature, may be used such as in bimetal spiral thermometers, or thermal power may be produced by largely completely suppressing the deflection of the element such power doing mechanical work and displacing regulating elements (e.g. bimetal ignition means in gas-heated equipment).
The known forms of bimetallic elements mainly consist of materials having different coefficients of thermal expansion secured together by welding, soldering, bonding and the like.
The known bimetallic elements do not fulfil all the important practical requirements. A particular disadvantage resides in the fact that with relatively broad bimetal strips the isotropy of the thermal expansion results in a very undesirable transverse curvature in addition to the required longitudinal bending, and this transverse curvature leads to mechanical stiffening of the strip. In this way, the required deflection is partly inhibited. In the known forms of bimetallic elements, which are based mainly on combinations of iron-nickel alloys, the choice of material is primarily determined by the thermal properties of the connected layers. This of necessity means that disadvantageous properties as regards electrical conductivity, corrosion-resistance etc., have to be accepted.
SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-stated disadvantages and to provide a bimetal element which possesses particularly advantageous properties. The invention is mainly characterized in that the element is made of a composite fiber material comprising at least one metallic component. Composite fiber materials of this kind contain randomly or specifically distributed fibers embedded in a matrix material, and in a preferred form, both the matrix material and the fibers are made of metallic materials. The composite fiber material can be produced by known metallurigcal methods, based for example on powder metallurgy, but it is advantageously produced by jointly coldshaping the matrix and fiber materials. The term composite fiber material is not, however, intended to be limited exclusively to purely metallic combinations in the present case, since for specific uses composite fiber materials of which the matrix or fiber material is nonmetallic, e.g. plastics material, can be produced.
To achieve the bimetal properties in an element in which the composite fiber material comprises a first component constituted by a matrix material and a second component constituted by at least one group of fibers embedded in the matrix material, it is advantageous that there is a coefficient of thermal expansion difference between the first and second components and/or between groups of fibers of the second component. Thus it is advantageous if the coefficients of thermal expansion of at least two groups of fibers embedded in the matrix material of the composite fiber material differ from each other, or if a matrix material is selected that has a coefficient of thermal expansion differing from that of at least one group of fibers embedded in the matrix material. These two possible methods may be combined with each other.
Where the bimetallic effect results from the differing coefficients of thermal expansion of embedded groups of fibers, the matrix material can be freely selected to meet particular additional requirements, namely, corrosion-resistance, specific weight, electrical and thermal conductivity, good mechanical deformability etc. Similarly, the fibers can be selected not only with the required coefficients of thermal expansion in mind, but also with a view to obtaining the necessary mechanical properties, electrical resistance, magnetic properties and so on. Use may also be made of combinations of materials as normally employed in the known bimetal elements. A considerable advantage of the element of the invention resides in the fact that the matrix material may be selected largely independently of the choice of the fiber that result in deflection of the element under the effect of heat. Furthermore, elements made of a composite fiber material do not become rigid, due to the isotropy of the thermal expansion, as do the known elements in the form of strips. The elements of the invention provide large deflections and large return forces.
In accordance with a further advantageous feature of the invention, the entire cross-sectional area of a group of fibers having a low coefficient of thermal expansion may be greater than the entire cross-sectional area of a group of fibers having a higher coefficient of thermal expansion, since generally the selected matrix material reinforces the expansion of the group of fibers having the higher coefficient.
Groups of fibers can be distributed in the matrix ma terial in various ways and in accordance with the required defiectional movement. In one advantageous form, the groups of fibers can be arranged in parallel layers; this arrangement appears to be particularly suitable in the case of elements in the form of strips. On the other hand, the use of the composite fiber material offers the possibility of making a torsional bimetal element in the form of a strip, this being achieved by arranging a group or groups of fibers over the crosssection of the matrix material in such a way that a temperature-responsive torsional moment results. In this connection, an asymmetric distribution of the groups of fibers in an element in the form of a strip is expedient, so that corresponding torsional moments can be obtained.
A further important improvement may be achieved by embedding, in the element, insulated fibers for electrical heating purposes and/or for conducting current.
By incorporating heating fibers or by appropriately selecting the fibers forming the fiber material, e.g., using the known nickel-iron alloys, which exhibit advantageous coefficients of thermal expansion as well as good electrical resistance properties, a thermoelectric, directly heatable control element can be formed in a simple manner.
The elements may be produced with a wide variety of cross-sectional forms having cornered and circular contours. Also, the dimensions of the elements can be suited to meet particular requirements.
BRIEF DESCRIPTION OF THE DRAWINGS Examples of elements having bimetal properties in accordance with the invention are illustrated in the accompanying drawings in which:
FIG. 1 is a perspective view of a sectioned element in which groups of fibers are distributed in parallel layers;
FIG. 2 shows an element having torsional properties, and
FIG. 3 shows an element in which there are groups of fibers having different cross-sectional dimensions.
DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows an element in the form of a strip and made of metallic matrix material 1 in which are embedded a first group 3 of metallic fibers having a low coefficient of thermal expansion and a second group 2 of metallic fibers having a higher coefficient of thermal expansion. When the element is heated, the strip acquires a convex upward curvature.
In the example illustrated in FIG. 2, the group of f1- bers 3 having the lower coefficient of thermal expansion is asymmetrically arranged in relation to the group 2 having the higher coefficient of thermal expansion so as to produce a torsional moment. When the element is appropriately heated, the strip 1 of matrix material twists about its longitudinal axis, so that direct rotary movements can be initiated in a particularly advantageous manner.
In the form shown in FIG. 3, the matrix material 1 is so selected that it reinforces the expansion of the second group 2 of fibers having the higher coefficient of thermal expansion, and it will be seen that the crosssectional distribution of the fibers of group 3 differs from that of the fibers of group 2. Also in this form insulated resistance-heating wires 4 are embedded between the two groups of fibers so that the strip-like element can be directly heated.
We claim:
1. A composite element having bimetallic properties and comprising:
a first component comprising a matrix material and having imbedded therein at least one additional component, each of said at least one additional components comprising a group of fibers;
at least one of said components being metal; and
one of said components having a coefficient of thermal expansion different from that of at least another of said components.
2. An element as claimed in claim 1, wherein said at least one additional component comprises a single group of fibers, and wherein said matrix material has a coefficient of thermal expansion different from that of said single group of fibers.
3. An element as claimed in claim I, wherein said at least one additional component comprises second and third additional components, each of said second and third components comprising a group of fibers.
4. An element as claimed in claim 3, wherein said matrix material has a coefficient of thermal expansion different from that of one of said groups of fibers.
5. An element as claimed in claim 3, wherein the group of fibers of said second component has a coefficient of thermal expansion different from that of the group of fibers of said third component.
6. An element as claimed in claim 5, wherein the total cross-sectional area of the fibers of that group having the lower coefficient of thermal expansion is greater than the total cross-sectional area of the fibers of that group having the higher coefficient of thermal expansion.
7. An element as claimed in claim 5, wherein said groups of fibers of said second and third components are arranged in separate layers in said matrix material, said layers being parallel.
8. An element as claimed in claim 5, wherein said group of fibers of said second component are imbedded in said matrix material asymmetrically of said group of fibers of said third component, whereby a temperature responsive torsional moment is created in said element.
9. An element as claimed in claim 1, further comprising electrically conductive fibers imbedded in said matrix material.
10. An element as claimed in claim 9, wherein said electrically conductive fibers form resistance heating

Claims (10)

1. A composite element having bimetallic properties and comprising: a first component comprising a matrix material and having imbedded therein at least one additional component, each of said at least one additional components comprising a group of fibers; at least one of said components being metal; and one of said components having a coefficient of thermal expansion different from that of at least another of said components.
2. An element as claimed in claim 1, wherein said at least one additional component comprises a single group of fibers, and wherein said matrix material has a coefficient of thermal expansion different from that of said single group of fibers.
3. An element as claimed in claim 1, wherein said at least one additional component comprises second and third additional components, each of said second and third components comprising a group of fibers.
4. An element as claimed in claim 3, wherein said matrix material has a coefficient of thermal expansion different from that of one of said groups of fibers.
5. An element as claimed in claim 3, wherein the group of fibers of said second component has a coefficient of thermal expansion different from that of the group of fibers of said third component.
6. An element as claimed in claim 5, wherein the total cross-sectional area of the fibers of that group having the lower coefficient of thermal expansion is greater than the total cross-sectional area of the fibers of that group having the higher coefficient of thermal expansion.
7. An element as claimed in claim 5, wherein said groups of fibers of said second and third components are arranged in separate layers in said matrix material, said layers being parallel.
8. An element as claimed in claim 5, wherein said group of fibers of said second component are imbedded in said matrix material asymmetrically of said group of fIbers of said third component, whereby a temperature responsive torsional moment is created in said element.
9. An element as claimed in claim 1, further comprising electrically conductive fibers imbedded in said matrix material.
10. An element as claimed in claim 9, wherein said electrically conductive fibers form resistance heating elements.
US00266351A 1971-07-20 1972-06-26 Element having bimetal properties Expired - Lifetime US3796100A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19712136171 DE2136171C3 (en) 1971-07-20 Shaped body with thermal bimetal properties

Publications (1)

Publication Number Publication Date
US3796100A true US3796100A (en) 1974-03-12

Family

ID=5814212

Family Applications (1)

Application Number Title Priority Date Filing Date
US00266351A Expired - Lifetime US3796100A (en) 1971-07-20 1972-06-26 Element having bimetal properties

Country Status (6)

Country Link
US (1) US3796100A (en)
CH (1) CH538681A (en)
FR (1) FR2146827A5 (en)
GB (1) GB1394103A (en)
IT (1) IT969404B (en)
SE (1) SE389557B (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1653378A (en) * 1922-07-01 1927-12-20 Westinghouse Lamp Co Method of making bimetallic wire
US3107532A (en) * 1961-04-14 1963-10-22 Gerdts Gustav F Kg Thermostat

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1653378A (en) * 1922-07-01 1927-12-20 Westinghouse Lamp Co Method of making bimetallic wire
US3107532A (en) * 1961-04-14 1963-10-22 Gerdts Gustav F Kg Thermostat

Also Published As

Publication number Publication date
DE2136171A1 (en) 1973-02-01
GB1394103A (en) 1975-05-14
CH538681A (en) 1973-06-30
IT969404B (en) 1974-03-30
DE2136171B2 (en) 1975-09-18
SE389557B (en) 1976-11-08
FR2146827A5 (en) 1973-03-02

Similar Documents

Publication Publication Date Title
US3102793A (en) Thermostat metal
US3520043A (en) Self-regulating heating elements
GB792145A (en) Improvements in and relating to devices for obtaining a mechanical movement from theaction of an electric current
US3767370A (en) Composite thermostat material
US2350029A (en) Inductive core
US3796100A (en) Element having bimetal properties
US2470753A (en) Thermostatic laminated metal
US2396196A (en) Controllable resistor
US4445367A (en) Hardness tester
US4041432A (en) Motor protector for high temperature applications and thermostat material for use therein
US3399076A (en) Method of wetting silicon nitride
US2405192A (en) Resistor
US3378357A (en) Temperature compensated magnetic field responsive material
US3902867A (en) Oxide dispersed high purity nickel for use in thermostat metals
US3223829A (en) Glass sandwiches primarily for windows of optical instruments
CA1077737A (en) Electrical temperature sensing device
US2863025A (en) Thermostats
US3712799A (en) Composite thermostat material
US3788821A (en) Composite thermostat material
US3098921A (en) Composite electrically heated devices
US4115624A (en) Thermostat metal compositions
Caliskan et al. The characterisation of bimetal disks used for thermostatic control and over-temperature protection
US3336119A (en) Element for sensing and controlling humidity and temperature changes
US3779718A (en) Corrosion resistant thermostatic laminate
US3512947A (en) Combined thermoflexural and magnetoflexural material