Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H37/00—Thermally-actuated switches
  • H01H37/02—Details
  • H01H37/04—Bases; Housings; Mountings
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H1/00—Contacts
  • H01H1/58—Electric connections to or between contacts; Terminals
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H1/00—Contacts
  • H01H1/12—Contacts characterised by the manner in which co-operating contacts engage
  • H01H1/14—Contacts characterised by the manner in which co-operating contacts engage by abutting
  • H01H1/20—Bridging contacts
  • H01H1/2025—Bridging contacts comprising two-parallel bridges
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H37/00—Thermally-actuated switches
  • H01H37/02—Details
  • H01H37/64—Contacts

Definitions

• the present invention relates to the field of thermal switches, and relates in particular to a thermal switch with a tamper-proof assembly and to its mounting method.
• Thermal switches also called temperature-actuated switches, electromechanical microswitches or thermal circuit breakers
• bimetallic switches are safety systems that allow a contact to be mechanically triggered, which opens a protected electrical circuit, when a overheating of the thermal switch.
• Thermal switches generally consist of an insulating box in which are mounted at least one pair of metal blades connected to a protected electrical circuit and a contact opening/closing mechanism between the blades of the at least one pair of blades actuated by temperature such as a heat-sensitive bimetallic disc or metal membranes connected to a heat-sensitive capillary.
• the protected electrical circuit may, for example, be part of a water heater or any other device such as an electric heater for private or collective use.
• the present invention aims to solve the drawbacks of the prior state of the art by proposing a thermal switch comprising an insulating casing in which are mounted at least a pair of metal blades and a contact opening/closing mechanism between the blades of the at least one pair of temperature-operable blades, the blades being locked in position in their own planes by means of positioning projections and being locked in position in the direction perpendicular to the planes of the blades by means of at least two crimping protrusions, the crimping of the at least two crimping protrusions thereby providing a tamper-proof assembly of the thermal switch, and also allowing a reduction in costs, since no additional components are necessary for guarantee the inviolability of the thermal switch according to the present invention.
• the present invention therefore relates to a thermal switch comprising an insulating casing in which are mounted at least one pair of metal blades and a contact opening/closing mechanism between the blades of the at least one pair of blades operable by the temperature, characterized in that the insulating casing comprises a first casing part and a second casing part, at least one of the first and second casing parts carrying, for each blade of the at least one pair of blades, at least one positioning projection which locks the position of said blade in its own plane, at least two crimping projections being carried by at least one of the first and second housing parts, the second housing part being mounted on the first housing part such that each of the at least two crimping projections passes through a corresponding through hole formed in the other of the first and second housing parts, the end free tee from each of the at least two crimping protrusions emerging from the corresponding through-hole and being configured to be crimped so as to block the position of the blades in the direction perpendicular to the plane
• the opening of a contact between the two blades of the same pair of blades when the contact opening/closing mechanism is actuated during an excessive temperature makes it possible to protect the users vis-à-vis an excessive rise in temperature of the electric water heater.
• the metal blades of the at least one pair of blades are completely locked in position in the insulating housing, the positioning projections allowing the blades to be locked in their own planes and the crimping of the free ends of the at least two crimping projections making it possible to clamp the second casing part to the first casing part and thus to block the blades in the direction perpendicular to the planes of the blades.
• metal blades can be arranged in the same plane or in different parallel planes.
• Crimping the free ends of the at least two crimping protrusions also helps ensure tamper-proofing of the thermal switch assembly.
• the positioning and crimping protrusions of the insulating casing allow the blocking of the metal blades and the closing of the insulating casing in a single operation, which makes it possible to assemble in a reliable and definitive manner all the components of the thermal switch. , in particular the metal strips allowing the passage of current and the contact opening/closing mechanism.
• the present invention thus makes it possible to reduce the number of operations and components during assembly, to avoid scrap (the thermal switch being removable and repairable until the last crimping operation) and to guarantee the operation of the drift-free thermal switch when in use.
• the present invention allows the product to be dismantled during manufacture, to improve the precision of the final product (more precise temperature), to increase the robustness of the product during handling by the installer and to reduce costs. assembly and the number of components.
• Closing the insulating box by crimping makes it possible to keep all the components in place and also makes it possible to detect any dismantling of the thermal switch on the customer's premises.
• the insulating casing has two crimping protrusions, these are preferably diametrically opposed.
• the thermal switch comprises a metal blade crimping projection.
• the thermal switch has four crimping projections distributed around the contact opening/closing mechanism.
• the present invention has the following advantages: fewer parts compared to existing solutions (e.g. four fewer metal rivets); more advantageous in terms of logistics, assembly and production costs due to the reduced number of parts; also allows tampering detection of the thermal switch, because the crimp cannot be repaired once destroyed.
• the height of the at least two crimping projections is greater than that of the positioning projections.
• the crimping protrusions of the insulating casing are higher to allow the stacking of the other components of the thermal switch, and to finally crimp the free ends of the crimping protrusions emerging from the corresponding through holes of the insulating casing, so as to assembling the first and second casing parts together to block the other components of the thermal switch inside the insulating casing.
• the at least two crimping projections are also positioning projections.
• the crimping projections allow both the locking of the blades in their own planes and the locking of the blades in the direction perpendicular to the planes of the blades.
• the insulating casing could comprise a single projection per metal blade, said single projection serving both as a positioning projection and as a crimping projection, said single projection being able, for example, to cross in an adjusted manner an orifice formed in the thickness of the corresponding blade then pass through the corresponding through hole of the insulating box to allow the crimping of its free end.
• each blade of the at least one pair of blades is blocked by three positioning projections and a crimping projection.
• each blade is locked in its own plane by the three positioning projections and the crimping projection, and is locked in the direction perpendicular to its own plane when the free ends of the crimping projections of the insulating casing are crimped. .
• notches are formed on each blade of the at least one pair of blades, said notches being complementary to the positioning projections for the insertion of the blades of the at least one pair of blades on positioning protrusions.
• Each notch can be a side notch or a central notch formed in the thickness of the corresponding blade.
• a notch is also formed on the blade for the insertion of the latter on the crimping protrusion.
• each positioning projection is a parallelepiped lug
• each crimping projection is one of a cylinder and a parallelepipedic lug surmounted by a cylinder.
• the notches of the slats are inserted on the parallelepipedal lugs of the projections so as to allow the locking of the slats in their own planes.
• the cylinders of the crimping projections pass through the corresponding through holes formed in the insulating casing, and then the free ends of the cylinders are crimped.
• the thermal switch comprises two pairs of blades having the same contact opening/closing mechanism.
• the same contact opening/closing mechanism makes it possible to simultaneously open the contact between the two blades of the first pair of blades and the contact between the two blades of the second pair of blades when the temperature becomes excessive.
• Each pair of blades can, for example, be connected to one of the power supply phases of the electrical network.
• the contact opening/closing mechanism comprises a heat-sensitive element deformable by temperature.
• the heat-sensitive element is configured to deform with temperature variations, said deformation causing the opening of the contact between the two blades of each pair of blades when the temperature exceeds a predefined temperature threshold.
• the second housing part consists of two elements between which the heat-sensitive element is blocked.
• the heat-sensitive element is locked in position between the two elements of the second casing part during the crimping of the free ends of the crimping projections, which makes it possible to improve the precision of the final product (more precise triggering temperature).
• the heat-sensitive element is one of a bimetallic disk and a heat-sensitive capillary connected to a metal membrane assembly.
• the heat-sensitive capillary is connected to a metal membrane assembly, preferably consisting of an outer circular metal membrane and an inner circular metal membrane, a liquid being present between the outer and inner membranes, the passage of said liquid in the vapor phase or well the expansion of said liquid when the temperature exceeds a certain threshold resulting in the deformation of the outer and inner membranes, which causes the opening of the contact between the two blades of each pair of blades.
• a metal membrane assembly preferably consisting of an outer circular metal membrane and an inner circular metal membrane, a liquid being present between the outer and inner membranes, the passage of said liquid in the vapor phase or well the expansion of said liquid when the temperature exceeds a certain threshold resulting in the deformation of the outer and inner membranes, which causes the opening of the contact between the two blades of each pair of blades.
• the external and internal diaphragms of the metallic diaphragm assembly can, for example, be made of steel (stainless, ferritic or low alloy).
• the heat-sensitive capillary may, for example, be of the twist or pin type (eg, copper), the interior of the capillary being in fluid communication with the interior of the metallic membrane assembly, the metallic membrane assembly and the capillary thus forming a thermostatic train.
• twist or pin type eg, copper
• the insulating casing is made of at least one material from among poly(butylene terephthalate), PBT, filled with glass fibers and polyamide 6, PA6, filled with glass fibers.
• the material used for the insulating casing has good fire resistance and is suitable for the plastic crimping of the free ends of the crimping projections.
• the present invention also relates to a method for mounting a thermal switch as described above, characterized in that it comprises the following steps: placing the at least one pair of blades on the first housing part such that the positioning projections lock the position of each blade of the at least one pair of blades in its own plane; arranging the contact opening/closing mechanism and the second housing part on the first housing part so that each of the at least two crimping protrusions passes through the corresponding through hole; and making a crimp on the free end of each of the at least two crimping protrusions emerging from the corresponding through hole so as to lock the position of the blades in the direction perpendicular to the planes of the blades.
• the plastic crimping of the free ends of the crimping protrusions is preferably done using gyroscopic crimping, but could also be done using radial riveting or orbital riveting, without deviate from the scope of the present invention.
• crimping could also be done by ultrasound. However, this technique is less preferred, since it poses temperature problems (too high temperature therefore approximate crimping due to the springback of the material).
• FIG. 1 is a perspective view of a thermal switch according to the present invention.
• thermal switch contact open/close mechanism is a side view of the thermal switch contact open/close mechanism
• FIG. 1 is a top view of the first housing part of the thermal switch, on which two pairs of blades are arranged;
• FIG. 1 is a perspective view of the ;
• FIG. 1 is a perspective sectional view of the thermal switch after crimping.
• thermal switch 1 according to the present invention.
• the thermal switch 1 comprises an insulating casing 2 in which are mounted first 3a and second 3b pairs of metal blades and a contact opening/closing mechanism 4 operable by temperature.
• thermal switch 1 could also comprise a single pair of blades or at least three pairs of blades, without departing from the scope of the present invention.
• the blades of the first and second pairs of blades 3a, 3b are arranged in the same plane, but could also be arranged in different parallel planes, without departing from the scope of the present invention.
• the contact opening/closing mechanism 4 is configured to simultaneously open/close a contact between the two blades of the first pair of blades 3a and a contact between the two blades of the second pair of blades 3b depending on the temperature.
• the contact opening/closing mechanism 4 comprises a metal membrane assembly 4a connected to a heat-sensitive capillary 4b of twist type, so as to form a thermostatic train for the thermal switch 1.
• heat-sensitive capillary 4b could also be of the pin or other type, without departing from the scope of the present invention.
• heat-sensitive capillary 4b and the metal membrane assembly 4a could also be replaced by a heat-sensitive bimetallic disc, without departing from the scope of the present invention.
• the insulating casing 2 comprises a first casing part 5 and a second casing part 6 between which the two pairs of blades 3a, 3b are blocked.
• the second housing part 6 consists of a first lower element 6a and a second upper element 6b between which the metallic membrane assembly 4a is locked in position, the second upper element 6b marrying the upper part of the membrane assembly metallic 4a.
• the first and second housing parts 5, 6 are assembled together by crimping the free ends of four crimping projections 7 formed on the first housing part 5 and passing through corresponding through holes 8 formed on the second housing part 6, so as to block the blades 3a, 3b and the opening/closing mechanism 4 inside the insulating casing 2.
• the crimping projections 7 could also be formed on the second casing part 6 and the through holes 8 formed on the first casing part 5, the crimping then being carried out in the lower part of the thermal switch 1, without departing from the scope of the present invention.
• some crimping protrusions 7 could be formed on the first casing part 5 and other crimping protrusions 7 formed on the second casing part 6, without departing from the scope of the present invention.
• the four crimping protrusions 7 are distributed around the metal membrane assembly 4a, arranged respectively at the four corners of the insulating casing 2.
• thermal switch 1 could also comprise only two diametrically opposed crimping projections 7, without departing from the scope of the present invention. Furthermore, the thermal switch 1 could also have three or at least five crimping protrusions 7, without departing from the scope of the present invention.
• the crimping of the free ends of the crimping projections 7 thus makes it possible to make the assembly of the thermal switch 1 tamper-proof.
• the insulating casing 2 is made of at least one material from poly(butylene terephthalate) (PBT) loaded with glass fibers and polyamide 6 (PA6) loaded with glass fibers.
• PBT poly(butylene terephthalate)
• PA6 polyamide 6
• the opening of the contact between the two blades of the same pair of blades 3a, 3b when the contact opening/closing mechanism 4 is actuated as soon as the temperature exceeds a certain temperature threshold makes it possible to protect users against an excessive rise in temperature of the electric water heater.
• Each pair of blades 3a, 3b can, for example, be connected to one of the electrical supply phases of the electrical network.
• the metallic diaphragm assembly 4a consists of an external circular metallic diaphragm (visible on the ) and an internal circular metallic membrane (not visible on the ).
• the external and internal membranes of the metal membrane assembly 4a can, for example, be made of steel (stainless, ferritic or low alloy).
• the interior of the capillary 4b is in fluid communication with the interior of the metal membrane assembly. 4a, a liquid being present between the outer and inner membranes of the metal membrane assembly 4a and in the capillary 4b, the passage of said liquid into the vapor phase or else the expansion of said liquid when the temperature exceeds a certain predefined threshold resulting in the deformation of the metal membrane assembly 4a in the thermal switch 1.
• a metal strip 9 is placed under the two strips 3b of the pair, a compression spring 10 placed under the metal strip 9 bringing the metal strip 9 into contact with the two blades 3b and thus establishing contact between the two blades 3b of the pair, such that the contact is normally closed.
• the contact opening/closing mechanism 4 further comprises a vertical slider 11 arranged between the lower part of the metal membrane assembly 4a and the upper part of the two metal strips 9.
• the deformation of the metal membrane assembly 4a when the temperature exceeds the predefined temperature threshold causes the downward movement of the vertical slider 11 and thus the downward movement of the two metal strips 9, which causes the opening of the contact between the blades 3a, 3b of the same pair.
• the contact is closed between the blades 3a, 3b of the same pair, and, when the metal membrane assembly 4a is curved downwards (temperature greater than or equal to the temperature threshold), the contact is open between the blades 3a, 3b of the same pair, which makes it possible to protect the electrical circuit connected to the blades 3a, 3b.
• support by the user on the vertical slider 11 at the rear of the thermal switch 1 is necessary to bring the metal strips 9 back into contact with the strips 9a, 9b and thus close the contacts.
• the first casing part 5 For each of the four metal blades 3a, 3b, the first casing part 5 carries three positioning projections 12 and a crimping projection 7.
• positioning projections 12 could also be carried by the second casing part 6, without departing from the scope of the present invention.
• the insulating casing 2 could carry any number of positioning projections 12, without departing from the scope of the present invention.
• Each of the four blades 3a, 3b has four lateral notches 13 complementary to the positioning projections 12 and corresponding crimping 7 for the insertion of the blade 3a, 3b on the positioning projections 12 and corresponding crimping 7, so that each blade 3a, 3b is locked in position in its own plane.
• the crimping projections 7 thus also serve as positioning projections for the blades 3a, 3b.
• At least one of the notches 13 could also be a central notch formed in the thickness of the blade 3a, 3b and crossed by one of the projections 12, 7, without departing from the scope of the present invention.
• the insulating casing 2 could also comprise a single projection per metal blade 3a, 3b, said single projection serving both as a positioning projection and as a crimping projection, said single projection being able for example to pass through a orifice formed in the thickness of the corresponding blade 3a, 3b then pass through the corresponding through-hole 8 of the second casing part 6 to allow the crimping of its free end.
• the height of the crimping protrusions 7 is greater than that of the positioning protrusions 12.
• Each positioning projection 12 is in the form of a parallelepiped lug
• each crimping projection 7 consists of a parallelepipedal lug 7a surmounted by a cylinder 7b.
• thermal switch 1 before crimping.
• the first lower member 6a of the second housing part 6 is mounted on the first housing part 5 such that each of the crimping projections 7 passes through a corresponding through hole 8a formed in the first lower member 6a of the second housing part 6.
• each of the crimping projections 7 passes through a corresponding through hole 8b formed in the second upper element 6b of the second casing part 6, the free end of each of the crimping projections 7 emerging from the corresponding through hole 8b and being configured to be crimped so as to block the position of the blades 3a, 3b in the direction perpendicular to the plane of the blades 3a, 3b.
• thermal switch 1 is shown there after crimping.
• Plastic crimping of the free ends of the crimping protrusions 7 is preferably carried out using gyroscopic crimping, but could also be carried out using radial riveting or orbital riveting, without s depart from the scope of the present invention.
• the metal blades 3a, 3b are completely blocked in position in the insulating casing 2, the positioning projections 12 and the parallelepipedic lugs 7a of the crimping projections 7 making it possible to block the blades 3a, 3b in their own planes, and the crimping free ends of the cylinders 7b crimping projections 7 making it possible to clamp the second casing part 6 to the first casing part 5 and thus to block the blades 3a, 3b in the direction perpendicular to the plane of the blades 3a, 3b.
• the crimping of the free ends of the crimping projections 7 thus makes it possible to guarantee the inviolability of the assembly of the thermal switch 1.
• the positioning 12 and crimping 7 protrusions of the insulating casing 2 thus allow the blocking of the metal blades 3a, 3b and the closing of the insulating casing 2 in a single operation, which makes it possible to assemble reliably and definitively all the components of the thermal switch 1, in particular the metal blades 3a, 3b allowing the current to flow and the contact opening/closing mechanism 4.
• the present invention allows the thermal switch 1 to be removable during manufacture, to improve the precision of the final product (more precise temperature), to increase the robustness of the product during handling by the installer and to reduce the assembly costs and the number of components.
• the closing of the insulating box 2 by crimping also makes it possible to detect a possible break-in of the thermal switch 1 on the customer's premises, given that the crimping cannot be repaired once destroyed.
• the rear part of the first casing part 5 also carries a screw thread 14 on which is mounted a nut 15, and a polarizer 16 to allow the thermal switch 1 to be fixed on a support.
• a method of mounting the thermal switch 1 comprises the following steps: arranging the first and second pairs of blades 3a, 3b on the first housing part 5 so that the positioning projections 12 block the position of each blade 3a , 3b in its own plane; arranging the contact opening/closing mechanism 4 and the second casing part 6 on the first casing part 5 so that each of the crimping projections 7 passes through the corresponding through hole 8; and make a crimp on the free end of each of the crimping projections 7 emerging from the corresponding through hole 8 so as to lock the position of the blades 3a, 3b in the direction perpendicular to the plane of the blades 3a, 3b.

Landscapes

• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Thermally Actuated Switches (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=74758929

Family Applications (1)

Country Status (3)

Family Cites Families (3)

• 2020
  • 2020-11-17 FR FR2011767A patent/FR3116376B1/fr active Active
• 2021
  • 2021-10-18 WO PCT/IB2021/059555 patent/WO2022106931A1/fr unknown
  • 2021-10-18 EP EP21805615.8A patent/EP4248472A1/de active Pending

Also Published As

Similar Documents

Legal Events