US2694194A - Oil burner safety shutoff switch - Google Patents

Description

Nov. 9, 1954 A. GILETTO OIL BURNER SAFETY SHUTOFF SWITCH 2 Sheets-Sheet 1 Filed Sept. 25, 1952 IN VENTOR. 4/7 L /70x79 Gf/e 1- f0 ATTUP FT S Nov. 9, 1954 A. GILETTO OIL BURNER SAFETY SHUTOFF SWITCH 2 Sheets-Sheet 2 Filed Sept. 25, 1952 m B m a Q INVENTOR. A/nhcmy Gi/ezzo ATTD RN EYE United States Patent OIL BURNER SAFETY SHUTOFF SWITCH Anthony Giletto, Philadelphia, Pa.

Application September 25, 1952, Serial No. 311,349

1 Claim. (Cl. 340-267) This invention relates to safety devices used primarily in combination with oil burners, and in particular a switch adapted to be installed on a stack or flue leading from a combustion chamber in which an oil burner is positioned with a plate extended into the stack, hinged to the extended end of an arm and adapted to be actuated by an explosion in the combustion chamber for operating a switch to open a circuit to a motor operating an oil burner and closing a circuit to a signal light indicating that the burner is inoperative.

The purpose of this invention is to prevent fire resulting from explosions in oil burner installations and to provide means for displaying a warning signal when such an explosion occurs.

In the conventional type of oil burner installation safety devices are provided to prevent continuous flow of fuel when ignition fails or when the operation of the burner stops for other reasons, however, even though the fuel flow stops temporarily gases from accumulations of fuel in the burner housing cause explosions when an attempt is made to start the burner or when the ignition system is actuated.

With this thought in mind this invention contemplates a switch positioned on a stack or flue leading from a combustion chamber in which parts thereof are mechanically connected to a door or baffle positioned in the stack or flue whereby with the door actuated by the force of an explosion the circuit to an operating motor of an oil burner of the installation is broken.

The object of this invention is, therefore, to provide means for forming a warning device whereby the device is actuated by the force of an explosion in a combustion chamber whereby a circuit to operating means of an oil burner or the like is stopped by the force of the explosion.

Another object of the invention is to provide a safety device for detecting an explosion in an oil burner installation in which the device may readily be installed on installations now in use.

A further object of the invention is to provide an explosion detecting and warning device particularly adapted for oil burner installations in which the device is of a simple and economical construction.

With these and other objects and advantages in view the invention embodies a switch box having a warning light therein with means for mounting the box on a stack or the like, and a rod extended from the box through the connection of the box to the stack and into the stack whereby the force of an explosion in the stack operates the switch through the rod.

Other features and advantages of the invention will appear from the following description taken in connection with the drawings, wherein:

Figure 1 is a vertical section through the device showing the switch box mounted on a stack, the stack also being shown in section, and the section being taken on line 1-1 of Fig. 2.

Figure 2 is a sectional plan through the explosion actuated switch taken on line 2-2 of Fig. 1.

Figure 3 is a section, similar to that shown in Fig. 2, looking upwardly toward the under side of the safety device.

Figure 4 is an elevational view looking toward the face of the switch box of the safety device.

Figure 5 is a cross section through the switch box of the safety device taken on line 5-5 of Fig. 3.

Figure 6 is a cross section through the switch box tended from the switch box into the stack through the door or battle, that operates the device.

Referring now to the drawings wherein like reference characters denote corresponding parts the improved oil burner explosion safety device of this invention includes a switch box 10 connected by a sleeve 11 to a stack 12 with a rod 13 journaled on supports 14 and 15 extended from the sleeve 11 and actuated by a door or baffle 16 through arms 17 and 18 whereby as the door 16 is forced open by an explosion the rod 13 is rotated to turn a trigger 19 whereby the trigger actuates a rocker arm 20 to disconnect contacts 21 and 22 at one end and connect contacts 23 and 24 at the opposite end whereby a circuit 15 broken to a motor for actuating an oil burner and another circuit is completed to a .light 25 which gives a warning indicating that an explosion has occurred.

The switch box 10 is carried by the sleeve 11 which is secured by a set screw 26 in a flange 27 of a ring 28 and the end of the sleeve extended through the rear wall 29 of the switch box is provided with a mounting flange 30 to which the operating parts of the switch are connected. An insulating bafile 31, spaced from the rear walls 29 of the switch box protect the box from heat of the stack.

The sleeve 11 is provided with a block 32, of insulating material and the block is secured in the sleeve with a set screw 33. The bars 14 and 15 are mounted in the block 32 and, as illustrated in Fig. 3 the bars 14 and 15 extend from the block 32 and the extended ends are connected with a cross bar or piece 34. The door 16 is pivotally connected to the cross bar 34 with a hinge 35 and, as illustrated in Fig. l, the door 16 is adapted to be moved outwardly as shown by the dotted lines whereby the arms 17 and 18 rotate the rod 13. The arm 17 is pivotally connected to the arm 18 with a pin 36 and as the door 16 is moved outwardly the arm 18 draws the lower end of the arm 17 toward the opposite side of the support whereby the rod 13 is rotated.

As the rod 13 is rotated the trigger 19 moves the contact end 37 of the rocker arm 20 away from the spring contacts 21 and 22 and in this movement the opposite end 38 of the rocker arm moves into position between the contacts 23 and 24, thereby completing a circuit to the light 25. The rocker arm 20 is pivotally mounted by a pin 39 in a bearing 40 and the extended edge of the arm is provided with a button 41 by means of which the arm may be returned to the position shown in Fig. 5. A spring 42, positioned between the rocker arm and a base 43 on which the contacts 21, 22, 23, and 24 are mounted, urges the rocker arm outwardly thereby assisting the trigger 19 in actuating the rocker arm to break the circuit to the motor and close the circuit to the light.

The contacts at one side of the switch are. grounded by a wire 44 and the circuit to the motor is completed by a wire 45 through a terminal 46 and a contact bar 47 to the contact 22. The circuit to the light is completed by a wire 48 which is connected to the terminal 49 on the contact 24.

The light bulb 25 is positioned in a socket 50, one terminal of which is grounded, and the other connected to the wire 48 through a contact 51.

The switch box is provided with a door 52 having an opening 53 through which the light 25 may be displayed and a knob 54 by which it may be opened and closed. The door is mounted on the switch box with hinges 55 and 56. The switch box is provided with a plurality of ventilating openings 57.

The arm 18 is attached to the door 16 with a clip 58 and the clip 58 is secured to the door with a screw 59. The bar 14 is provided with a bearing 60 in which the extended end of the rod 13 is journaled and the opposite end of the rod is journaled in the flange 30 on the end of the sleeve 11.

The switch box 10 is provided with an outlet nipple 3 61 through which the wires for the electrical connections extend.

Although the device is shown and described as providing a visible signal it is understood that the circuit completed by the rocker arm as a result of an explosion may 1also sound an alarm or provide a suitable audible signa.

It Will be understood that modifications, within the scope of the appended claim, may be made in the design and arrangement of the parts Without departing from the spirit of the invention.

What isclaimed is:

In combination, a stack provided with an opening therein, a flange surrounding said opening and secured to said stack, a sleeve projecting through said flange and into said stack, a switch box including a rear wall provided with an opening for receiving said sleeve, an insulating bafile spaced from said rear Wall for protecting the switch box from heat from the stack, a block of insulating material secured within said sleeve, a pair of bars extending from said block, a crosspiece intercom meeting the free ends of said bars together, a door hingedly connected to said crosspiece, a rod rotatably positioned in said stack, arms pivotally connecting said rod to said door for rotating said rod upon pivotal movement of said door, a trigger actuated by said rod,

pivotally mounted in said bearing and having a button thereon, said rocker arm abutting said trigger, a coil spring arranged in engagement with said rocker arm, an indicating member positioned in said switch box, a first pair of contacts connected to said indicating member and adapted to be engaged by an end of said rocker arm, and a second pair of contacts in said box -for connection to a motor and adapted to be engaged by the opposite end of said rocker arm.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 659,855 Meloon Oct. 16, 1900 989,132 Dewey Apr. 11, 1911 1,171,192 Haas Feb. 8, 1916 1,693,309 Mettler Nov. 27, 1928 2,013,225 Waters Sept. 3, 1935' 2,244,373 Powers June 3, 1941 2,421,768 Voliazzo et al. June 10, 1947 2,646,476 Landry July 21, 1953- 1 2,659,334 Fiedler Nov. 17,, 1953

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