US2601892A - Burner control system - Google Patents

Description

y 1952 w. D. HALL 2,601,892

BURNER CONTROL SYSTEM Original Filed Dec. 4, 1945 F/c l 78 I valve 83.

Patented July l, 1952 UNITED STAT ES PArs QFFICE 632,673. Divided and this application August 2, 1949, SerialNo. 108,091

Claims. (01. 158 28) This invention relates to control systems and more particularly to means; for controlling a burner. The primary object ofthis invention is to provide a simple and inexpensive control'system that is safe in operation. Other objects of the invention include the provision of means whereby the control operations are performed rapidly when rapid operation is desired for safety reasons.

Briefly speaking the detailed character of the invention is that a massive slidable member is moved by a bimetallic strip, which strip is responsive to the heat from the burner, and the position of this member controls the energization of the igniter. The fuel flow to the burner is controlled in accord with the lost-motion action of the slidable member and the bimetallic strip. The circuit to the fuel controller of the burner is closed for a limited time period by mechanically bringing together contacts which may be respectively located on the bimetallic strip and the slidable member. Further details of the invention will hereinafter appear as will further objects and advantages.

In the drawings, Figure l is a diagrammatic view of one form of the invention and Figure 2 is a diagrammatic view of another form of the invention. Both views show their respective systems in the off positions thereof.

This application is a division of my prior copending application Serial No. 632,673, filed December 4, 1945, entitled Burner Control System, now U. S. Patent No. 2,503,260, granted April.

11, 1950. The subject matter of thepresent patent was originally disclosed in said earlier application S. N. 632,673 as filed on December 4, 1945, but was cancelled therefrom after the application on which the present patent issued was filed.

I will now describe the construction and mode of operation of Figure 1. A burner 80 has a hotwire igniter BI and a solenoid 82 controlling the A rigid supporting member 84 supports the sliding massive member 81. The latter is arranged to slide unbiased on the supporting member 86. A bimetallic strip 85 rigidly supported at its lower end is arranged to be engaged by sliding member 81 when the latter is moved to the right sufficiently, and the resilient strip 86 (which is fixed at its upper end) is likewise arranged to engage member 81 when the latter is moved to the right. Strips l9- and 99 are supported at their upper ends, and strip 99 is resilient so that. it may be moved to the left by arm 98 when block 81 is sufiiciently moved to the left. For the purpose of moving member 81 to the right there is provided a push button 91 attached to rod 83. Rod 98 is heldin a normal 01f position by a nut 89 which engages the inside of fixed heater wall section lfiil'. On the outside of the wall section 116. is a spring 93 whichis compressed between the push button 9! and wall section {55. Spring 90 retains the push button 9! in the normal off position as shown. As an alternative to manually depressing push button in, a mechanical device 92 (designated Ii/ID) of any character, for example a time clock,'may be employed.

The operation of Figure 1 is as follows: By depressing push button 9|, the slidable member 8"! is forced into contact with strips and 85. This closes circuits to the igniter and valve through supply lines IT and i8 as follows: 18- 99-l984.8l-858l-'-161l; and 18-99- 'i98 lB'l--6582lGll. Hence the igniter is energized and valve 83 opens causing fuel'to flow to the burner 86. Now assume that the burner temperature goes too high; the bimetallic strip '85 will move block-81 to the left and the insulation arm 98 willyen'gage resilient arm 99- and breakthe circuit to solenoid 82. If the flame ignites and'the burner thereafter operates in the normal and expected way, the bimetallic strip 85 will move block 81 sufficiently to the left to break the circuit between contact 86 and block Bl thereby deenergizing the igniter 8!; however block 81 will not move farenough to deenergize the circuit through contacts 19 and 99-. If the burner satisfactorily ignites and continues to heat, but not excessively, and the flame should accidentally go out, the bimetallic strip 85 moves block '81 to the left-until the flame goes out and then strip 85 will reverse its direction and disengage slidable member 8'5 thus opening the circuit to the valve. An ordinary switch 16 maybe employed to shut down the system.

Referring to Figure 2- there is shown a source of electrical supply 209, 268, a hot-wire igniter 251i and two rigidly mounted bars 292 and 291 which respectively carry the slidable members 263 and 296. Complementary contacts '294 and 295are respectively mounted on said members. A bimetallic strip 209 is rigidly mounted at its lower end and carries contact point 2!! at its upper end which may engage contact point 2l8 upon motion of the parts. A handle 2!! may be used for starting the apparatus, which handle is held by spring 2 l2 in separated position from the wall 2"]. The handle 2 II carries rod 2 M which rod carries stop 2l3. A flexible wire 215, which has no electrical function, but purely mechanical functions, is connected between rod 2 l4 and slidable member 203. Motor M serves to supply fuel to the system.

To place the system of Figure 2 into operation, knob 2| l is pulled to the left, which action pulls wire 2 I 5 taut and then pulls slidable member 203 to the left. The movement of member 203 to the left causes contacts 204 and 205 to engage, and if the knob 2!] is pulled still further to the left (which is not necessary) the member 203 will move member 206 to the left. The ngagement of contacts 204 and 205 closes the circuit to the igniter After the knob 21! has been pulled out it is then quickly pushed in until member 206 closes contacts 218 and 2M starting the fuel motor (or valve) M. Fuel therefore starts to fiow and assuming it is ignited, th heat therefrom will cause bimetallic member 209 to move to the left. Since the knob 2!! has been released, the member 206 is moved away from member 203, thus deenergizing igniter 20!. Fuel contacts 211, 2(8, however, remain close as long as the burner gives off heat. Should the flame accidentally go out, strip 209 will cool and thereby separate contacts 211, 2| ti, thereby stopping fuel flow. The device may be restarted at any future time by again pulling knob 21! and then pushing it clear in. It is desirable that rod 2 be composed of insulating material and that insulating beads (not shown) be placed around wire 2 l 5.

I claim to have invented:

1. In a heating system, a burner, an igniter for the burner, a slidable member, a thermal element responsive to the heat of combustion of said burner which deflects when heated, means supporting the first end of the thermal element to locate the second end adjacent said sliding member, said second end and said sliding member being normally spaced from each other and the thermal element being so positioned that when heated the second end moves toward the sliding member, means mounting the slidable member for sliding movement and including means permitting the slidable member to be moved to a position where it is in contact with said second end when the thermal member is in its cool condition as attained when the burner has been off for such an extended period that the thermal element has attained ambient temperature, fuel fiow control means for the burner operable to admit fuel flow when said second end contacts said slidable member and stops fuel flow when said second end is separated from said slidable member, contact means which closes a circuit therethrough when said slidable member is moved to said position and which opens the circuit therethrough when said thermal member moves the slidable member away from said position, and a circuit connected. in series with said contact means for controlling said igniter.

2. In a heating system, a burner, an igniter for the burner, a slidable member, a thermal element for driving the slidable member and fixed at a first end and movable toward and away from the slidable member at its second end, said thermal element being subject to the heat of combustion at the burner, means mounting the slidable member for such extensive sliding motion that the same may be moved into a predetermined relative position with respect to said second end when the thermal element is at ambient temperature, fuel control means including a circuit controller which effects fuel flow when the slidable member and said second end are in said predetermined relative position, and a circuit controller for said igniter controlled by said slidable member.

3. The system defined by claim 2 including in addition a manually movable element for moving the slidable member into said predetermined position.

4. In a burner control system, a circuit for controlling fuel feed, an igniter for the burner, a slidable member, circuit controlling means for closing the igniter circuit only when the slidable member is in a predetermined position, means mounting the slidable member for such extensive motion as to be movable to said predetermined position, a thermal element responsive to the heat of combustion of said burner having one end thereof fixed and the other end thereof arranged to move the slidable member away from said-predetermined position in response to heat, said other end being so positioned when cool that it is engaged by said slidable member when the latter is moved to said predetermined position, circuit control means for controlling the fuel circuit according to the relative position of said other end and said slidable member, and manual means including biasing means for normally biasing the manual means so it does not affect the operations of the foregoing parts, said manual means including mounting means enabling the manual means to move said slidable member to said predetermined position.

5. In a burner control system, an igniter for the burner, a fuel circuit including fuel control means for the burner, a pair of slidable members, means mounting said members for motions toward and away from each other, a thermal element responsive to combustion fixed at one end and having a free end normally spaced from the first of said slidable members and movabletoward and away therefrom, manually operable means for moving said slidable members together and thereafter moving the said first slidable member into contact with said free end, circuit control means for the igniter controlled by the relative position of the slidable members, and additional circuit control means for the fuel circuit controlled by the relative position of said free end and said first slidable member.

WILLIAM D. HALL.

REFERENCES CITED The following references are of record in the file of this patent? UNITED STATES PATENTS Number Name Date 1,693,070 Crane Nov. 27, 1928 2,399,673 Hall May 7, 1946

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