US3389361A - Thermostatic switch construction having fixed contacts and movable contacts means therebetween - Google Patents

Description

3 June 18, 1968 s. E. MANECKE 3,339,331

THERMOSTATIC SWITCH CONSTRUCTION HAVING FIXED CONTACTS AND MOVABLE CONTACTS MEANS THEREBETWEEN' Original Filed Oct. 23, 1965 '3 {Sheets-Sheet 1 FIG-4 i 43 46 42 40W: (1 1 J'fig; 66 3 7| 74 72 633; 73 64 3. 58 6| 2| 68 a f 69 77? 4 S L 49 56 5 76 E\...|.. v I ll 24 INVENTOR. Q

SIEGFRIED E. MANECKE Midwh HIS ATTORNEYS June 18, 1968 5, MANECKE 3,389,361

' THERMOSTATIC SWITCH CONSTRUCTION HAVING FIXED CONTACTS AND MOVABLE CONTACTS MEANS THEREBETWEEN Original Filed Oct. 23, 1965 4 Sheets-Sheet 2 INVENTOR. SIEGFRIED E. MANECKE H IS ATTORNEYS June 18 1968 S E- MANECKE THERMOSTATIC SWITCH ONSTRUCTION HAVING FIXED CONTACTS Original Filed Oct.

F I G 5 2? 24 J zs E 36 AND MOVABLE CONTACTS MEANS THEREBETWEEN 4 Sheets-Sheet :5

FIG-6 IOAI 22 43A 42A 46A 62A IZIA 1 I [IV II null INVENTOR. SIEGFRIED E. MANECKE HIS ATTORNEYS June 18, 1968 S. E. MANECKE THERMOSTATIC SWITCH CONSTRUCTION HAVING FIXED CONTACTS AND MOVABLE CONTACTS MEANS THEREBETWEEN Original Filed Oct. 23 1965 4 Sheets-Sheet 4 IOO Y INVENTOR. SIEGFRIED E. MANECKE BY M paw HIS ATTORNEYS United States Patent 3,389,361 THERMOSTATIC SWITCH CONSTRUCTION HAV- ING FIXED CONTACTS AND MOVABLE CON- TACTS MEANS THEREBETWEEN Siegfried E. Manecke, Indiana, Pa., assignor to Robertshaw Controls Company, Richmond, Va., a corporation of Delaware Continuation of application Ser. No. 503,289, Oct. 23, 1965. This application Sept. 21, 1967, Ser. No. 669,651 Claims. (Cl. 337-347) ABSTRACT OF THE DISCLOSURE This disclosure relates to a thermostatically operated electrical switch construction having a pair of fixed electrical contacts and a spring blade having contact means on one end thereof with that end being disposed between the fixed contacts, the spring blade having its movable end directly interconnected to the movable end of a .bimetal member by a tie bar so that movement of the movable end of the bimetal member in response to changes in sensed temperature will cause the contact means to move between and engage one or the other of the fixed contacts in response to the particular direction of movement of the bimetal member. One' of the fixed contacts is adjustable toward and away from the other contact.

This application is a continuation of application Ser. No. 503,289, filed Oct. 23, 1965, now abandoned.

This invention relates to an improved compact thermostatic switch construction as well as to improved parts for such a switch construction or the like.

It is well known that thermostatic switch constructions have been provided for domestic water heaters and the like wherein the switch construction thermostatically controls the temperature of the water heater tank by closing and opening contact means to respectively energize and deenergize electrical heater means for the water heater tank in accordance with the temperature sensed by the thermostatic switch construction in order to maintain the temperature of the water in the water heater tank at the selected temperature.

One feature of this invention is to provide such a thermostatic switch construction wherein the various parts thereof are relatively simple to manufacture and assemble to provide a thermostatic switch construction which is not only accurate but very compact.

Accordingly, it is an object of this invention to provide an improved thermostatic switch construction having one or more of the novel features set forth above or hereinafter shown "or described.

Another object of this invention is to provide improved parts for such a switch construction or the like.

Other objects, uses and advantagesof this invention are apparent from a reading of this description which proceeds with reference to the accompanying drawings forming a part thereof and wherein:

FIGURE 1 is a front perspective view of the improved thermostatic switch construction of this invention.

FIGURE 2 is a front view of the switch construction illustrated in *FIGURE '1.

FIGURE 3 is a rear view of the switch construction illustrated in FIGURE 1 with the mounting bracket means thereof removed.

FIGURE 4 is a cross-sectional view of the switch construction of FIGURE 1 and is taken on line 44 of FIGURE 2.

FIGURE 5 is a view similar to FIGURE 4 illustrating the switch construction in another operating position thereof.

3,389,361 Patented June 18, 1968 "ice FIGURE 6 is a view similar to FIGURE -4 and illustrates another embodiment of this invention.

FIGURE 7 is a fragmentary schematic view illustrating the switch constructions of this invention in a control system of this invention.

FIGURE 8 is a schematic view similar to FIGURE 7 and schematically illustrates the working parts of the switch constructions of FIGURE 7.

While the various features of this invention are hereinafter described and illustrated as being particularly adaptable for providing a thermostatic control for a domestic water heater tank or the like, it is to be understood that the' various features of this invention can be utilized singly or in any combination thereof to provide a switch construction for other devices as desired.

Therefore, this invention is not to be limited to only the embodiments illustrated in the drawings, because the drawings are merely utilized to illustrate one of the wide variety of uses of this invention.

Referring now to FIGURE 1, the improved thermostatic switch construction of this invention is generally indicated by the reference numeral 10 and comprises a housing means 11 having an opened rear side 12, FIGURE 3, closed by a mounting bracket means 13 fastened to the housing means 12 and being adapted to secure the thermostatic switch construction 10 to the desired supporting structure by fastening means passing through suitable apertures 14 in ear means 15 of the mounting bracket 13 or by having suitable mounting clamps engage cars 16 of the mounting bracket 13 in a conventional manner.

Thus, it can be seen that the mounting bracket 13 is readily adaptable to secure the thermostatic switch construction 10 of this invention to the external wall of a domestic water heater tank or the like whereby the thermostatic switch construction '10 will sense the wall tank temperature for a purpose hereinafter described.

The housing 11 has opposed recess means 17 formed in the opposed sides thereof and respectively defining shoulders 1'8. The mounting bracket 13 has a pair of side flanges 19 provided with spring fingers 20 which are adapted to snap into the recesses 17 of the housing 11 when the housing 1 1 and bracket 13 are assembled together in the manner illustrated in FIGURE 1 whereby the spring fingers 20 engage against the shoulders 18 of the housing 11 to hold the housing 11 and bracket 13 in their assembled relation.

A bimetal member 21 is disposed in the cavity 22 of the housing 11 and has one end 23 fastened to a middle leg 24 of a leaf-like spring member 25 having the outer legs 26 respectively fastened to a retainer means 27 and to the housing 11 by rivet type of fastening means 28. The retainer means 27 has an outwardly directed tongue 29 adapated to pass through a slot 30 in the bracket means 13 in the manner illustrated in FIGURE 4 to pivotally mount the bracket means 13 to the housing 11.

The retainer 27 has a threaded bore 31 passing therethrough and threadly receiving a threaded adjusting member 32 projecting out through an opening 33- in the housing 11 and carrying a temperature indicator pointer 34 cooperable with a temperature setting dial plate 35 secured to the front surface 36 of the housing 11. The adjusting member '32 has a bifurcated end 37 to permit the adjusting member 32 to be rotated relative to the retainer 27 by the insertion of a screwdriver or the like in the bifurcated end 37 so that the threaded member 32 can be threaded inwardly and outwardly relative to the retainer 27, and thus, adjust the position of the end 23 0f the bimetal member 21 relative to the housing 11 to set the thermostatic switch construction 10 to operate at a desired sensed temperature in a manner hereinafter set forth.

As the threaded member 32 is adjusted relative to the housing 11, it can be seen that the pointer means 34 moves in unison therewith and cooperates with the dial 35 to indicate a particular temperature setting for the thermostatic switch construction 10. In this manner, the thermostatic switch construction 10 can be adjusted to tend to maintain the temperature of the water in the water heater tank at the temperature indicated by the pointer 34.

The other end 38 of the bimetal member 21 is provided with three legs 39, 40 and 41 with the middle leg 40 being stepped out of the plane of the legs 39 and 41 so that when the legs 39-41 are received in a slot m ans 4 2 of an insulated tie-bar 43, the end 38 of the bimetal member 21 is press fitted in the slot means 42 of the tiebar 43 to prevent any lost motion between the movement of the movable end 38 of the bimetal member 21 and the tie-bar 43.

The other end 44 of the tie-bar 43 has a slot means 45 receiving the free end 46 of a snap acting spring blade 47. The other end 48 of the spring blade 47 is interconnected by fastening means 49 to a terminal plate 59 fastened to the housing 11 by an internally threaded terminal post 51, FIGURE 3.

The spring blade 47 is divided into three legs 52, 53 and 54 intermediate its ends 46 and 48 with the outer legs 52 and 54 being crimped at 55 to place the middle leg 53 under compression and render the blade 47 snap acting.

A leaf-type spring 56 has an end 57 also secured to the terminal plate 50 by the fastening means 49 and is secured to the middle leg 53 of the spring blade 57 by a fastening means 58 whereby the free end 59 of the leaf spring 56 bears against a threaded adjusting member 60 threadedly carried in a threaded bore 61 formed in the housing 11.

In this manner, the adjusting member 60, in cooperation with the leaf spring 56, determines the force required to move the blade 57 with a snap movement from the position illustrated in FIGURE 4 to the posit on illustrated in FIGURE 5 for a purpose hereinafter described.

The spring blade 47 carries a contact means 62 on the end 4-6 thereof which is cooper-able with either a contact means 63 carried by a terminal plate 64 fastened to the housing 11 by an internally threaded rivet-like terminal post 65 or with a contact means 66 carried on a terminal plate 67 and fastened to the housing 11 by a fastening means 68, one end 69 of the terminal plate 67 having a threaded bore 70 passing therethrough to provide a terminal post means for the thermostatic switch construction 10 in a manner hereinafter described.

The end 71 of the terminal plate 67 is normally urged by the natural resiliency of the plate 67 flat against the housing 11 to the position illustrated in FIGURE 4. However, a threaded adjusting member 72 is threadedly carried in a threaded bore 73 in the housing 11 and is adapted to engage the end 71 of the terminal plate 67 to adjust the position of the end 71 of the terminal plate 67 relative to the housing 11 whereby the spacing between the c Eintact means 63 and 66 can be adjusted to any suitable limit.

Therefore, it can be seen that a suitable external lead can be electrically interconnected to the contact means 63 by being fastened to the terminal post 65 by a threaded fastening member 74 whereby the terminal plate 64 electrically interconnects the terminal post 65 to the contact means 63. Similarly, an external lead can be electrically interconnected to the movable contact means 62 by being attached to the terminal post means 51 by a threaded fastening member 75 whereby the terminal post means 51 is electrically interconnected to the contact 62 by the terminal plate 50 and electrically conduct ing spring blade 47.

A third terminal lead is adapted to be electrically interconnected to the contact 66 by being fastened to the end 69 of the terminal plate 67 by a threaded fastening member 76 being received in the threaded bore 70 of the terminal plate 67 whereby the terminal plate 67 electrically interconnects the lead at the fastening member 76 to the contact means 66.

As illustrated in FIGURE 4, the mounting bracket means 13 of the thermostatic switch construction 10 has an opening 77 passing therethrough adjacent the bimetal member 21 so that the bimetal member 21 will tend to sense the temperature of the water heater tank wall d sposed against the exterior surface of the bracket means 13.

Another thermostatic switch construction of this invention is generally indicated by the reference numeral 10A in FIGURE 6 and parts thereof identical to like parts previously described for the theromstatic switch construction 10 are indicated by like reference numerals followed by the reference letter A.

As illustrated in FIGURE 6, the thermostatic switch construction 10A is identical to the thermostatic switch construction 16 previously described except that the terminal plate 67 and its contact 66 and lead fastening means 76 are'eliminated, as well as the previously described adjusting screw 72. However, a larger adjusting screw 78 is threadedly disposed in the threaded bore 73A of the housing means 11A and is adapted to project into the cavity 43A whereby the end 79 of the adjusting screw 78 provides a stop means for the contact means 62A when the same is moved away from the contact means 63A for a purpose hereinafter described.

Therefore, it can be seen that the thermostatic switch constructions 10 and 10A of this invention are relatively simple to manufacture and assemble while being readily utilizable for thermostatic control of a water heater tank or the like.

For example, the switch constructions 1t) and 10A can be utilized independently from each other or may be utilized in combination in a manner now to be described.

In particular, reference is now made to FIGURES 7 and 8 wherein it can be seen that the thermostatic switch constructions 10 and 10A are adapted to be respectively secured to the external wall 80 of a water heater tank or the like with the switch construction 10 being disposed above the switch construction 10A a desired distance so that the switch construction 10 senses the temperature of the water in the water heater tank 80 at a point above the water that the thermostatic switch construction 10A senses the temperature thereof.

The thermostatic switch construction 10 is adapted to thermostatically control the operation of an upper electrical heater means 81 while the thermostatic switch construction 10A is adapted to thermostatically control the operation of a lower electrical heater means 82 for the water heater tank 80.

In addition, a high limit thermostatic safety switch construction 83 is secured to the wall 80 of the water heater tank and has four terminal means 84, 85, 86 and 87 with the terminal means 84 and 85 normally being electrically interconnected together by thermostatically operated switching means 88 while the terminal means 86 and 87 are normally interconnected together by thermostatic switching means 89, the switching means 88 and 89 operating in unison so that when the switch construction 83 senses a temperature in the water heater tank 80 above a safe limit, the switching means 88 and 89 move to the right in FIGURE 8 to break the electrical connection between the terminal means 84, 85 and 86, 87 until the same are reset in their closed positions by a reset button 90.

A pair of power leads L and L are respectively interconnected to the terminal means 84 and $6 of the safety limit switch construction 83. The terminal 85 of the safety limit switch construction 83 is interconnected to the terminal means 75 of the switch construction 10 by a rigid bus-bar type of lead 91. The terminal means 74 of the switch construction is interconnected to one side 92 of the upper electrical heater 81 by a lead 93 while the other side 94 of the electrical heater 81 is interconnected to the terminal 87 of the safety limit switch construction 83 by a lead 95.

The terminal means 76 of the switch construction 10 is interconnected to the terminal means 75A of the lower thermostatic switch construction 10A by a lead 96. The terminal means 74A of the thermostatic switch construction 10A is interconnected to one side 97 of the lower electrical heater 82 by a lead 98 while the other side 99 of the lower electrical heater '82 is interconnected to the lead 95 by a branch lead 100.

Therefore, it can be seen that to electrically interconnect together the switch constructions 10A and 83 in combination with the heater means 81 and 82 of the water heater tank 80 involves a relatively simple procedure.

The operation of the thermostatically operated control system generally indicated by the reference numeral 101 in FIGURES 7 and 8 will now be described.

As illustrated in FIGURE 7, the operator sets the adjusting screw means 32 and 32A of the thermostatic switch constructions 10 and 10A to the desiredtemperature setting positions thereof whereby the thermostatic switch construction 10 will tend to maintain the temperature of the water in the water heater tank adjacent the thermostatic switch construction 10 at the set temperature of the adjusting screw 32 thereof by means of the upper heater means 81 while the lower thermostatic switch construction 10A will tend to maintain the temperature of the water in the water heater tank 80 adjacent the thermostatic switch construction 10A at the temperature set by the adjusting screw means 32A there-' of through the operation of the lower heater means 82.

As illustrated in FIGURE 8, the switch constructions 10 and 10A are respectively disposed in the positions illustrated in FIGURES 4 and 6 whereby the spring blade 47 of the switch construction 10 is holding the contact means 62 into electrical contact with the contact 63 to electrically interconnect the terminal means 75 and 74 while the spring blade means 47A of the lower thermostatic switch construction 10A is maintaining the contact 62A into electrical contact with the contact 63A to electrically interconnect together the terminal means 75A and 74A.

With the thermostatic switch constructions 10 and 10A in the position illustrated in FIGURE 8, the bimetal members 21 and 21A are sensing temperatures of the water in the water heater tank below the temperature settings for the particular thermostatic switch constructions 10 and 10A. However, during this condition, only electrical current is being supplied to the upper heating element 81 whereby the heating element 81 is heating the water in the water heater tank 80. 7

However, when the temperature of the Water adjacent the thermostatic switch construction 10 reaches or exceeds the set temperature for the thermostatic switch construction 10, the free end 38 of the bimetal member 21 tends to move to the right in FIGURE 4 in opposition to the force of the spring blade 47 until the force of movement of the free end 38 of the bimetal member 21 overcomes the force of the spring blade 47 and causes the same to move with a snap movement from the position illustrated in FIGURE 5 whereby the electrical connection between the terminal means 74 and 75 is terminated and, thus, the fiow of electrical current to the upper heater means 81 is terminated.

However, with the upper thermostatic switch construction 10 now in the position illustrated in FIGURE 5, it can be seen that the terminal means 75 and 76 thereof are electrically interconnected together whereby, with the thermostatic switch construction 10A in the position illustrated in FIGURE 8A, current is now supplied to the lower heater means 82 to operate the same. When the temperature of the water sensed by the lower thermostatic switch construction 10A reaches or exceeds the set temperature of the thermostatic switch construction 10A, the bimetal member 21A of the thermostatic switch construction 10A moves the contact 62A away from the contact 63A with a snap movement against the end 79 of the stop member 78 whereby the flow of current between the terminal means 74A and 75A is terminated and, thus, the flow of electrical current to the lower heater means 82 is terminated.

Accordingly, it can be seen that when the temperature of the water sensed by the thermostatic switch construction 10 falls below the selected temperaure thereof, the end 38 of the bimetal member 21 moves back to the left and carries the contact 62 therewith with a snap movement to again place the same in electrical contact with the contact 63 and out of electrical contact with the contact 66 whereby the current is again supplied to the upper heater 81 for the purpose previously described. Similarly, when the temperature sensed by the lower thermostatic switch construction 10A falls below the selected temperature thereof, the bimetal member 21A has caused the contact 62A to move With a snap action into electrical contact with the contact 63A whereby the terminal means 74A and 75A thereof are electrically interconnected together so that current can again flow to the lower electrical heater means 82 when the upper thermostatic switch construction 10 interconnects together the terminal means 7 S and 76 thereof in the manner previously described.

Accordingly, it can beseen that the switching function of the system 101 of this invention operates in a manner to tend to maintain the temperature of the water in the water heater tank at various levels therein at selected temperatures.

However, during the operation of the heater means 81 and 82 of this invention in the manner previously described, should the safety limit switch. construction 83 sense a temperature above a safe limit thereof, the switching elements 88 and 89 thereof terminate the electrical connection between the terminals 84, 85 and 86, 87 thereof to prevent operation of the heater means 81 and 82 until the thermostatic switch construction 83 is reset by the reset means 90.

Accordingly, it can be seen that this invention not only provides an improved thermostatic switch construction which operates in an accurate manner while being relatively compact, but also this invention provides improved parts for such a thermostatic switch construction or the like.

What is claimed is:

1. A control device comprising a housing, a bimetal member disposed in said housing and having an end movable in response to temperature sensed by said bimetal member, a pair of fixed contacts carried by said housing, a spring blade carried by said housing and having a movable end carrying contact means cooperable with said contacts, a tie bar interconnecting said end of said bimetal member with said end of said spring blade to cause said contact means to move between said contacts in response to movement of said end of said bimetal member, said device having means for adjusting the position of one of said fixed contacts relative to the other fixed contact to vary the spacing therebetween, said adjusting means comprising a plate member having opposed ends, one of said ends of said plate member carrying said one fixed contact and the other end of said plate member providing terminal means for said one fixed contact, means fastening said plate member to said housing intermediate said ends of said plate member, said plate normally tending to hold said one end thereof in one position against said housing, said housing carrying an adjusting member for engaging said one end of said plate so that adjustment of said adjusting member relative to said housing adjusts said one end of said plate relative to said housing to vary said spacing between said fixed contacts.

2. A control device as set forth in claim 1 wherein said plate member is angled between said ends thereof whereby said ends are offset relative to each other.

3. A control device as set forth in claim 2 wherein said angled plate member defines an elbow thereof, said fastening means fastening said plate member to said housing adjacent said elbow thereof.

4. A control device as set forth in claim 1 wherein said housing has an opening therein, said other end of said plate member being exposed at said opening to provide said terminal means for said one fixed contact.

5. A control device as set forth in claim 4 wherein said other end of said plate member is offset relative said one end thereof to extend into said opening of said housing for lead attaching purposes.

References Cited UNITED STATES PATENTS 2,689,290 9/1954 Mertler 200---l38 2,823,283 2/1958 Malone 200138 2,958,744 11/1960 Engle 200-166 3,238,337 3/1966 Rosenberg et a1 200-438 3,263,051 7/1966 Gauthier et a1. 200l70 BERNARD A. GILHEANY, Primary Examiner.

R. L. COHRS, Assistant Examiner.

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