Патент USA US3061718код для вставки
Oct. 30, 1962 'r. H. STIEBEL 3,061,707 PRESSURE TEMPERATURE OPERATED ELECTRICAL SWITCHING APPARATUS Filed Oct. 20, 1959 2 Sheeis-Sheet 1 uv l/EN TOR THEOOO H. S 776'BEL. Oct. 30, 1962 T. H. STIEBEL 3,061,707 PRESSURE-TEMPERATURE OPERATED ELECTRICAL SWITCHING APPARATUS Filed Oct. 20, 1959 2 Sheets-Sheet 2 INVENTOR B y THEOO I? H. ST/EBL'L l Free 3,061,707 Patented Oct. 30, 1962 2 mations of the casing may occur, causing sticking of the 3,061,707 movable components of the switch. PRESSURE-TEMPERATURE QPERATED ELECTRI However, in accordance with this invention, these dis CAL SWITCHING APPARATUS advantages can be avoided by no longer housing the Theodor Hermann Stiebel, Luchtringer Weg 11, pressure responsive element and the electrical switch Holzminden (Weser), Germany mechanism each in separate regions of the handle casing. Filed Oct. 20, 1959, Ser. No. 847,509 An object of the invention is to eliminate the need 10 Claims. (Cl. 219-41)‘ for justi?cation of the relative positions of the pressure This invention relates to an electrical switching ar responsive element and the switch per se by permanently rangement within a casing or head actuatable by a hy 10 ?xing their relative positions before assembling them with draulic drive by way of a force transmitting member. the housing or handle. The drive per se consists of a probe tube terminating in a pressure sensitive element, the probe tube preferably Still a further object is to facilitate the installation of the heating element and the pressure-temperature respon containing a thermally expansive liquid. The pressure sive switching mechanisms in cooking utensils and vessels, variations are transmitted to the pressure responsive ele 15 and to permit ready replacement thereof with a minimum ment either directly by way of the temperature acting or“ simple assembly and disassembly operations. on the free, closed end of the probe tube or indirectly, I accomplish the foregoing, and other, objects by pro in the manner known from the manometer art, by way viding an insulating plate upon which both the pressure of an open probe tube end. responsive element and the electrical switch are mounted, Temperature disconnect switches or control devices which mounting plate is readily insertable in a housing employing these principles are used, for example, in im< or handle. So to mount the pressure-temperature respon mersion heaters. In such heaters it is prior knowledge to sive member, the latter is provided with tongue-like pro house the electrical switch and the pressure sensitive ele jections which preferably are inserted through corre ment (a membrane or a bellows) separately, each in sponding apertures or grooves in the mounting plate and one of the half-shells of the handle casing or in one 25 are bent over, and/or twisted, to the rear thereof while of the handle casing portions, and to separate them by the electrical switch and the line connections are sup means of an insulating plate clamped between the parts ported on the face of the mounting plate remote from a of the handle casing, the plate having an aperture or ?exible wall or membrane of the pressure-temperature recess for a pressure transmitting element. Such im responsive member. The so assembled parts provide a mersion heater is, for example, shown in Patent 2,902,581 structure which is as simple as possible, is fully self for “Miniature Immersion Heater With Electric Con troller Sealed in Handle,” issued to me on September 1, 1959. The predetermined relative position of the pressure re sponsive element and the electrical switch for obtaining positive switching sequences is assumed thereby only after assembly of the handle casing in immersion heater handles so constructed. Consequently, only after assem bly of the complete device can it be ascertained whether the switching temperature is the required temperature. Subsequent justi?cation is then practically impossible, par ticularly where the half-shells of the handle, or the cas ing components, are joined, as by welding them together, contained and independent of the position of the casing portions relative to each other, is positively operable at the predetermined desired temperature of the heated con tents of the cooking utensil, and completely and readily interchangeable. If desired, this structure can be atq tached to a handle or housing portion by means of a screw simultaneously serving as a portion of a line con nector. - Where the handle casing consists of a bell-shaped hous ing into the open end of which a ?anged plate is in sertable which supports both of the end regions of the tubular heater and the probe tube and simultaneously serves as the sealing cover, such as shown in my copend as occurs extensively in making handles for immersion 45 ing application for patent, Serial Number 812,935, ?led heaters of synthetic materials. It is, of course, conceivable that the actuating mecha nism of a justifying arrangement, in the form of a regulat May 13, 1959, for “Watertight Handle for Immersion Heaters,” it is recommended that the mounting plate be anchored to the tubular heater connecting terminals which, ing screw, be brought out through the handle housing; for this purpose, are made rigid and preferably in the but by so doing the immersion heater handle is no longer 50 form of lugs of known type, and are mechanically con— watertight. Furthermore, in such a construction, the nected rigidly to the line connector supported on the point at which the switch operates to open the heater mounting plate. circuit might be irresponsibly altered by an unauthorized To increase the stability of the switching arrangement according to the invention within elastic handle housings, adjusted to above the boiling point, might, in the least 55 indirectly mechanically supporting the same by way of objectionable case, be actuated during ordinary heating, the temperature probe tube on the ?anged plate, has been that is, below the boiling point; or vice versa, a tempera found to be appropriate. Hence, the instant invention ture regulating arrangement normally operating at below further proposes to make the temperature probe tube the boiling point may fail completely, that is, not be ac rigid at least from the ?exible membrane of the pressure tuated at all when the disconnect point is adjusted to a 60 temperature responsive member to its exit portion beyond temperature above the boiling point. the ?anged plate, or to reinforce the per se readily de Likewise, in the case where a temperature disconnect fortmable temperature probe tube with an enveloping rigid arrangement is housed in the immersion heater handle, the sleeve or tube at such region. In addition, the mounting . predetermined relative position of the parts housed in plate can advantageously be secured in its position by i‘ the individual half-shells of the handle or in the indi 65 providing tongue-like extensions at the edge thereof to-‘ vidual portions of the handle housing will not be ob ward the ?anged plate and providing corresponding re: .tained positively, where these handle portions are, wholly cesses in the ?anged plate. The mounting plate, prior or partially, of a material of perceptible elasticity, pref to making the electrical connections, is then forcibly and erably synthetics. In the course of reclosing the switch positively inserted into the recesses. Furthermore, it has by thumb-pressure on the portions of the handle provided 70 been found advantageous, in addition to supporting the therefor, below which the temperature and pressure re structure (switch, pressure-temperature responsive mem sponsive switching element is located, undesirable defor ber, and mounting plate) at one side of the ?anged plate, person. Thus, an excess temperature disconnect switch, 3,061,707 3 I , 1 4 to push the mounting plate drawerlike, with its lateral (FIGURE 3) in mounting plate 18 and are twisted or sides in grooves provided therefor Within a portion of the bent over on the other side against the mounting plate to support the casing thereon. A hollow rivet 23 fastens housing, into the housing, or, vice versa, to push the hous ing provided with grooves over the assembled complete mounting plate. By so doing damage to the electrical switching arrangement either on pushing the mounting one end of a contact spring 24 to the other face of the mounting plate, that is, to its surface opposite membrane 2%, a button 25 of electrical insulating material being carried by the contact spring. ‘Button 25 extends through an aperture 26 de?ned by the mounting plate with one end of the button engaging resilient membrane 2t) and its exerted upon it, is avoided. Two illustrative embodiments of the invention are now 10 other end engaging a soft, manually depressible region 27 plate in, or on manual reconnection of the switch be cause the mounting plate has too great a bending moment descraibed in detail with the aid of the annexed draw ing, in which: FIGURE 1 shows a top view, partially in section, of a ?rst embodiment of the invention comprising a heating element combined with a temperature-responsive dis connect switch installed in a container for heating liquids; FIGURE 2 an exploded perspective view or" the switch ing head of the embodiment of FIGURE 1 in the order in which the head is assembled; FIGURE 3 a section along line III-III of FIGURE 2 showing the temperature responsive member and the dis connect switch assembled with the mounting plate as a unitary component; FIGURE 4 a section along line IV~—IV of FIGURE 1; FIGURE 5 a section along line V-V of FIGURE 1; FIGURE 6 a longitudinal view, partially in section, of of cover 17 ‘(FIGURE 4). spring 24 carries a contact a ?xed strip contact 31} which in turn is connected to The free end of contact 29 which is juxtaposed to on the mounting plate, an elongated contact lug 31 (‘FIGURES l and 4) which at its opposite end electrical ly connects with a bow or loop 32 in recess 41 of body 141 into which one rigid terminal 33 (FIGURE 4) of heat ing element 3 is slid on assembly of the heating element with base 1% to electrically connect that side of the heat ing element to strip contact 30. The electrical connection of terminal pin 15 to con tact spring 24 is by way of a conductor 34 in base 10, conductor 34- terminating in a metal nut 35 sunk in supporting surface 36 of base It) for mounting plate 15}. A metal bolt 37 is threaded into nut 35 and in con ductive contact extends into the hollow rivet 23 which a second embodiment of the invention in an electric im holds mounting plate 18 and contact spring 24 together. mersion heater handle with the handle casing open; FIGURE 7 a section along line VII-VII of FIG URE 6; !FIGURE 8 a section along VIII—VIII of FIGURE 6; Thus metal bolt 37 serves in a ?rst aspect as a current supply member, and in second aspect to af?x tempera ture switching arrangement 4 to body 11). The elec trical connection of terminal 16 to the other end of heater FIGURE 9 a view of the second embodiment similar coil 3 is by way of a direct connection in the form of a metal tube 39 embedded in body It} and end 28 of body 11) adjacent to vessel 2, into which the correspond to the view of F-IGURE 6 but with the handle casing 35 ing connecting pin 33’ of the heater coil slides on as closed. sembly exactly as does connecting terminal pin 33 into Referring to the drawing, the ?rst illustrative embodi ment of my invention is shown in FIGURES 1 through loop 32. Assembly of pressure-temperature switching arrange 5. Through an aperture 1 de?ned in the cylindrical wall ment 4 with heater element 3, and the installation there of a vessel '2 for heating liquids, for example a water kettle, a tubular heating element 3, of known construc 40 of, proceed as follows: The above described pressure temperature switching arrangement 4 constructed as a tion per se, projects into the interior of the vessel and is completely independent structural element, with mount provided, exterior to the vessel wall, with a temperature responsive disconnect switching arrangement 4. The heater end of heating element 3, broken away and not shown in FIGURES 1 and 3, maybe in the form of a hol low cylinder or an open helical coil, the latter being shown in FIGURES 6 and 9. The switching arrange ing plate 18 positioned on supporting surface 36 and laterally in guide grooves 40 of body 10, is slid into the base body whereby contact lug 31 and loop 32 are posi tioned in a suitably formed recess 41 provided, as has been stated, in the base body. Thereupon metal bolt 37 is tightly screwed through metal nut 35, and cover tending into the vessel and containing a thermally ex 117, with its dove-tailed shaped lateral edges 42 in corre pansible liquid 6. The probe tube 5 is enveloped by pro 50 sponding grooves 43 of the base body, is slid into the base body as previously was the mounting plate, where tective pipe 7 which is connected by heat conductive by the rim of recess 44 in end 38, adjacent to vessel 2, bridge 8, at its region extending into vessel 2, to tubular of cover 17, slides on the temperature probe tube until heating element 3. The shanks of the heating element 3, a longitudinal extension 45 of the mounting plate, to together with pipe .7, pass through plate ?ange 9, on the interior surface of the wall of vessel 2, to rigid base 55 wards the end of the insertion, enters into, and termin ates in, a corresponding opening 46 in such cover end body 10 of a material non-conductive both thermally and 38, so that mounting plate 18, which is subjected to a electrically, positioned on the exterior surface of the wall of the vessel of a switch housing or head. Obviously, the bending stress on re-connection of the switch, as below end of protective pipe 7 within vessel 2 is closed to pre described, also has a support at its ‘forward end which vent leakage of the liquid being heated into the switching 60 otherwise is not supported on supporting surface 36. arrangement. Base body 10 and rim region 12 of the The assembled switch head is ‘so placed in front of aper vessel wall de?ning aperture 2 are rigidly and tightly ture 1 and plate ?ange 9 positioned in back thereof, ment 4 is provided with a temperature probe tube 5 ex sealed, by bolts 13 and packing 14, to plate ?ange 9, with the baseiody serving as the housing for temperature re— sponsive‘switching arrangement 4 (FIGURES 2 and 3), while simultaneously inserting the probe tube 5 pro jecting therefrom into protective tube 7, that metal tube 65 39 and loop 32 of contact lug 31 on pushing it further forward in the direction of plate ?ange 9, will push over the terminal pins 33, 33’ of heater 3. Thereupon the g switch housing-as initially stated-is bolted to plate able cover 17. ?ange 9. Dismantling and disassembly of the switch The switching arrangement 4 per se is a?‘ixed to mount ing plate 18 of electrically insulating material and con 70 housing is obviously in the reverse order. The switching sequence is as follows: Spring mem sists of a relatively ?at, pressure casing 19, connected to brane 21), as the result of the increasing pressure applied the temperature probe tube 5, and the pressure casing to it with increasing temperature of the liquid in vessel wall facing the mounting plate is provided with a resilient 2 by thermally expansible liquid 6 in temperature probe membrane 20. The pressure casing is provided also with tongues 21 which pass through corresponding slots 22 75 tube 5, which liquid 6 can be of such type that when the as also for terminal pins 15 and 16 (FIGURES 4 and 5) connectable to the electric line, and is provided with slid 5 3,061,707‘ liquid to be heated or the heating coil reaches the pre determined switching temperature it evaporates, is dis tended to such a degree that it snaps into its convex position (FIGURES 3, 4) thereby lifting insulating but ton 25 in impact-like manner, by which action contact 29 is moved away from ?xed contact strip 30 with the re 6 head or the housing wall, and the membrane 20 is so constructed that it has but a single normal position, at which the switch is closed, to which at all times it tends to restore even when distended sufficiently to open the switch. What I claim is: sult that the heating circuit is opened. Such snap-action I. A switching arrangement for electrical heaters in direct heat transferring contact with liquids to be heated in detail in my copending application above mentioned. comprising an electrical heating element having a pair Reconnection of the current is obtained manually by 10 of terminals, a ?xed ?rst contact, a spring of electrically depressing soft portion 27 of cover 17. When so do conductive material of which one end is spatially ?xed, ing, the insulating button 25 is depressed to such extent a second contact supported at the free end region of the membranes for pressure casings are shown and describedv as to exert su?‘icient pressure on the resilient membrane spring end movable to engage with the ?rst contact, a 20 that the latter will spring back into its opposite, or pair of line supply conductors of which one is connected concave (and connect) position, shown in FIGURES 3 15 to one of the ?rst and second contacts and the other to and 4 by the dashed or broken lines. Simultaneously, one terminal of the heating element, the other of the ?rst prebiased contact spring 24 will spring back into its and second contacts being connected to the other terminal connecting position when contact 29 presses tightly of the heating element, a hollow housing of electrical against ?xed contact strip 30. and thermal insulating material, a longitudinal internal The immersion heater of FIGURES 6 through 9 is, 20 shoulder in each of a pair of opposite longitudinal walls with minor variations, provided with the same switching of the housing, a support plate of insulating material slid arrangement as shown in FIGURE 3. Like reference ably supported on the housing shoulders, the ?rst contact characters in this embodiment denote the same elements and the spatially ?xed end of the spring being attached as in the ?rst, and above described, illustrative embodi to one longitudinal face of the support plate, a heat probe ment. Speci?cally, the following changes in construc 25 tube in heat transfer relation with the heating element, tion are involved in this second illustrative embodiment a thermally expansive liquid within the heat probe tube, of the invention. The protective tube 7 for probe tube a closed reservoir into which the heat probe opens hav 5 is dispensed within the switch housing, constructed in ing one wall which is ?exible, a pin of insulating ma— the form of the handle for the immersion heater, is terial supported in and extending through the spring, one not, as in the ?rst embodiment, adapted for incorporation 30 end of the pin engaging the ?exible wall of the reservoir, or building into a heating vessel and thus need not, even the support plate de?ning a central aperture through temporarily, be separated from the heating element. The which the pin extends, and means mounting the heat form of the handle housing of this second embodiment probe tube and the reservoir on the longitudinal face of renders inadvisable the use of the threaded connection the support plate opposite to that to which the ?rst con of a conductive bolt 37 and a conductive nut 35 as in .35 tact and the ?xed end of the spring are attached. the ?rst embodiment. 2. The switching arrangement according to claim 1 in Furthermore, the form of the direct connection made by metal tube 39 from the connecting line 47 to the terminal prong of the heater 3 is, in this embodiment, in which the support plate is mechanically positioned in the housing by a metallic threaded member threaded into and through the spatially ?xed end of the spring, through the form of a conductor 89' directly supported on mount 40 the support plate and into the housing wall, the threaded ing plate 18 to maintain bell-shaped, thin handle 48, free member electrically connecting to one of the line supply of all conductors. Handle housing 48 is made of a per— conductors. ceptibly elastic thin walled synthetic material in order 3. 'In combination with a vessel for heating liquids, an to obtain the soft portion 27 by thinning the wall thick immersion heater of which the heating coil of the im ness of the handle housing, and, as below described, 45 mersion heater extends through an aperture de?ned in to connect the handle housing with the ?anged cover the heating vessel wall, means sealing the heating coil plate 9'. Loop 32 (32') and contact lug 31 (31’), in liquid tight within the vessel with its terminals external this embodiment, are provided at each connecting ter to the vessel, a housing of electrical and thermal insulat minal 33 (33') of heating element 3 with such terminal ing material external to the vessel, the housing de?ning a pins being of rigid material to function as supports for cavity into which the terminals of the immersion heater mounting plate 18 and being soldered to the loops upon extend, a heat probe extending through the sealing means previously having inserted extension 45 of the mounting and containing a thermally expansive liquid, a closed con plate into aperture 49 of ?anged cover plate 9’. The tainer into which the end of the probe external ‘to the ves two last-mentioned expedients, together with sleeve 50 sel connects, one wall of the container having a ?exible extending through cover plate 9' and reinforcing tem 55 region, a support plate of insulating material within the perature probe tube 5, function to stabilize the inter housing cavity, an electrical switch having a spring throw connection of mounting plate assembly 18, having switch biased to closure and connectable to a line supply of elec~ ing arrangement 4 mounted thereon, with ?anged cover trical potential, means supporting the switch and the con— plate 9’. Such immovable and rigid disposition of the tainer on the plate, an insulating member supported in and switching arrangement relative to the ?anged cover plate 60 extending through the spring throw of the switch and ex is absolutely required also for the reason that on as tending through an aperture de?ned in the plate to engage sembling bell-shaped handle housing 48, which guides the container ?exible wall, and a ?exible portion in a the lateral edge regions of mounting plate 18 in grooves 51 during such assembly, the housing on further ‘advance ment must be positioned in a predetermined relation to ?anged cover plate 9' when the bell-shaped housing, automatically distending its open rim end 52., tightly en gages rim 53 of ?anged cover plate W with internal an nular projection 54 of the bell-shaped housing. As will be obvious to the skilled worker in the art, the temperature disconnect switch in both switch head 11 and in handle housing 48 may house a temperature reg ulating arrangement, that is, a controller, in place of the disconnect switch shown in both embodiments. In such case, there is no need for a soft portion 27 in either the wall of the housing aligned with insulating member for depressing the insulating member manually to restore the container ?exible region and the switch each to its pre operated condition after operation thereof by the ex pansion of the thermally expansive liquid at a predeter mined temperature. 4. The combination of claim 3 in which the heat probe is removably within a protective pipe integral with the sealing means and extending into the vessel, and a heat conductive bridge connects the protective pipe to the heating coil. 5. The combination of claim 3 in which the housing consists of a body de?ning a longitudinal recess extending 3,061,707 8 8. The switching arrangement according to claim 7 in which a plurality of elongated projections integral with the enclosure extend through apertures de?ned in the from one end of the body to close its other end, and a cover having an integral ?ange at one end to close the open end and the top of the recess when slid into the supporting plate and are deformed at their ends project .ing beyond the plate securely to attach the enclosure to the plate, and a rivet attaches one end of the movable body, the body has a pair of grooves in opposite longi tudinal walls for guiding the support plate with the switch and the container mounted thereon into the cavity of contact to the support plate. 9. The switching arrangement according to claim 7 in which a hollow, electrically conductive, rivet a?'ixes the recess, a conductive threaded member passes through one contact of the switch and the insulating plate into the body when the plate is in its predetermined position with in the cavity, a line conductor is embedded in the body 10 one end of the movable contact to the support plate and has an externally threaded portion extending through the and electrically connected to the threaded member, a longitudinal projection is integral with the trailing end of the support plate, the projection extending into an support plate, the other side of the line supply being connected to an internally threaded, electrically conduc tive, member embedded in the housing into which the extending portion of the rivet is screwed, to mechanically position the support plate at the predetermined position within the housing and to attach the support plate to the aperture de?ned in the integral ?ange of the cover on closing the cover on the body with the plate in its prede termined position, and means secure the body with its cover closed to the sealing means. housing. 6. The combination according to claim 5 in which the body de?nes a second recess, a pair of line terminals is disposed within the second recess of which one terminal is connected to the line conductor embedded in the body, 10. The switching arrangement according to claim- 1 in which the housing consists of a bell-shaped body and a cover ?tted over the open end thereof, the spring is biased to closure of its free end on the ?rst contact and a conductive tube is embedded longitudinally in the body and connected at one end to the other line terminal, and a conductive rod embedded transversely in the body con nected at one end to the other switch contact with the plate in its predetermined position, the other end. of each conductive tube and the conductive rod electrically engaging the terminals, respectively, of the immersion is movable by the pin moved by the ?exible Wall of the reservoir at a predetermined elevated temperature of the “ liquid within the reservoir to disengage the free spring end from the ?rst contact, and one wall of the body has a ?exible portion registering with the insulating pin when the cover is secured to the body with the plate at a prede termined position within the housing for manually de pressing the ?exible body portion to depress the insulating pin after the liquid within the reservoir has cooled from heater. 7. A switching arrangement actuatable at a predeter~ mined temperature to disconnect an electrical supply line in which it is connected comprising an enclosure having at least one pressure-sensitive wall, a thermally expansive the predetermined elevated temperature to restore both the ?exible wall of the reservoir and the ?exible portion liquid ?lling the enclosure, an electrical heating element of the body to their preoperated positions, both the ?ex for connection to the electrical supply line, a portion of ible portion of the body and the ?exible wall of the reser the enclosure remote from its ?exible wall being ex voir being su?iciently stiif that with pressures thereon in posed to heat from the heating element, a ?xed elec either the outward or the inward direction of magnitudes trically conductive contact electrically connected to one less than that corresponding to the predetermined ele side of the heating element, the other side of the heating vated temperature they each retain the position deter element being connected to one side of the line supply, 4.0 mined by the last applied pressure and the direction a movable electrical contact electrically connected to the thereof. other side of the line supply, the movable contact nor References Cited in the ?le of this patent mally engaging the ?xed contact, a support plate of elec trical insulating material on one face of which the ?xed UNITED STATES PATENTS and movable contacts are mounted while the enclosure 45 is mounted on the opposite face thereof, an interconnec tion of electrical insulating material passing through an aperture de?ned in the support plate between the ?exible wall of the enclosure and the movable contact, an open top housing of electrical insulation material, a pair of 50 spaced longitudinal shoulders on opposite walls of the housing adjacent the open top of the housing, and a cover 1,620,183 1,833,996 2,024,060 2,369,986 2,432,169‘ Bersted _____________ __ Mar. 8, Johnstone et al _________ __ Dec. 1, Peralta _____________ __ Dec. 10, Schaefer _____________ __ Feb. 20, Morgan et al. ________ __ Dec. 9, 1927 1931 1935 1945 1947 \ 2,576,688 Landgraf ____________ __ Nov. 27, 1951 2,732,478 Stiebel ______________ __ Jan. 24, 1956 of electrical insulating material for the housing supported 2,902,581 Stiebel ______________ __ Sept. 1, 1959 on the shoulder the nearer to the open top of the housing, » 2,977,456 Stiebel _____________ -_ Mar. 28, 1961 the support plate being slidably supported on the other 55 shoulder.