US2082029A - Stoker alarm - Google Patents

Description

' June 1, 1937. J. ROLAND STOKEH ALARM Filed April 2'7, 1955 IE 2m \ZMHIIIIMII/IM INVENTOR. db/r/v [Four/v0,

ATTORNEY-'5.

Patented June 1, 1932 UNITED STATES PATENT OFFICE Schwitzer-Cummins Company,

Ind., a corporation Indianapolis,

Application April 27, 1935, Serial No. 18,535 7 Claims. (01. 171-311 This invention relates to an automatic signal or alarm applicable to stokers to indicate failure of operation.

When the feed screw of a stoker is blocked for any reason, such as by a rock, rail spike or other' obstruction becoming lodged therein, its operation is, necessarily, discontinued. To that end, stokers are usually equippedas a protection against overload, with various overload or pressure release devices that will operate to release the drive or discontinue it. Thus, in mechanically driven stokers, the driving pin may be sheared or withdrawn, gears unmeshed or a clutch released. Again, the circuit to the electric drive motor may a be broken. In. stokers embodying hydraulic power transmissions there is provided a by-pass valve to relieve hydraulic pressurasuch as will prevent continued driving operation of the screw feed while the driving motor continues its operation.

It is the purpose of this invention to equip such device with an alarm which will call attention to the stoker should it become inoperative through obstruction or the like. Wherein attention is not called thereto, the stoker may cease to function, allowing the fire to get low or go out. In such instances such a situation may.result in substantial damage, or perhaps merely discomfort. Thus, it is desirable to call attention to such condition by an alarm which will be effective, depending upon the character and purpose of the installation. As an example, wherein a stoker is employed in a greenhouse and may be left without attention for considerable lengths of time, it is desirable to provide an alarm at a remote station, such as in the ofiice of the greenhouse, to give warning that the stoker has stopped functioning. By means of this invention there is provided a device for giving an alarm, either at the stoker or at the station remote therefrom, upon the stoker becoming inoperative through an obstruction or the like. The alarm may also be equipped with means for breaking the circuit to the driving motor so as to prevent wear and tear on the parts and consumption of current during the non-operation of the stoker, all as will be hereinafter more fully set forth and described.

The full nature of the invention will be understood from the accompanying drawing and the following description and claims: Fig. 1 is a perspective view showing an application of one type of alarm. Fig. 2 is a front elevation. of the alarmcontrol showing the wiring diagram therefor. Fig. 3 is a front elevation of a portion of the alarm actuating inechanilm.

The invention is herein described as being applied to a hydraulic power transmission of a stokeras more particularly set forth in Letters Patent to Carl J. Winkler and Herman E. Winkler, No. 1,968,188, issued July 31, 1934. However, the invention may be likewise applied to other types of stoker power transmissions, such as a gear driven stoker.

In the drawing there is illustrated a section III of the power transmission housing which is provided on the forward face thereof with a switch box II. Mounted within said housing there is provided a cylinder I2 into which oil is pumped by a pump driven 'by a motor I3, the piston in ,the cylinder I2 actuated by the pressure of the oil pump therein driving the usual feed screw of the stoker through a pawl and ratchet drive, the shaft of said feed screw extending through -a bearing I4 in the forward face of the housing, all as fully illustrated in the above-mentioned Letters Patent.

Mounted on the cylinder I2 and in communication with the interior thereof, there is provided a pressure control by-pass valve I5 which is illustrated in Fig. 1 of the above-mentioned Letters Patent indicated by the numeral 46 and referred to therein as fdllows: Communicating with the 2 upper portion of the cylinder there is a blow-off valve indicated at 46 in Fig. l for relieving the pressure upon being excessive, such as may be caused by an obstruction to the movement of the piston."

For ordinary domestic use and for local alarm. said by-pass valve I5 may be provided with a whistle or any other construction therein which will produce sufficient sound to attract attention. Said valve is constructed in the usual manner to withstand the normal pressure of the piston in the operation of the stoker and only permit bypassing of the oil from the piston upon the pressure substantially exceeding normal pressure by reason of obstruction to normal driving operation, as is well understood in the art.

For the purpose of giving alarm at a remote point, a cup I6 is mounted on a shaft H in such position with respect to the valve I5 as to receive the full force of the oil forced therethrough upon the pressure in the cylinder being abnormally excessive due to obstruction. The force exerted by the discharge of oil through the valve against the base of the cup I6 causes partial rotation of the shaft H which is mounted in suitable bearings and extends through the front face I0 into the switch box II.

Mounted upon the forward end of the shaft 55 tion.

there is a trip lever ll provided with a latch I! on the outer end thereof. Pivotally mounted within the box ii there is a mercury switch 20 supported by a plate 2|, the free end of which is supported by the shoulder of the latch I! on the lever I8. Said switch is so positioned in the box II that upon being released by the lever I! it will drop down to the position indicated by dotted lines to break one circuit and make another circuit, as will be hereinafter described. Slidably mounted to extend through the bottom of the switch box ii there is a plunger 22 which may be manually manipulated to raise plate 2! carrying the switch 20 so as to reset the switch after operation. Thus, after the switch has been released by the latch l8 and the stoker trouble remedied, the plunger 22 may be pushed up to reset the switch in latched position.

The switch 20 has its pivoted ends connected to the motor II by the wire 22 and to a source of energy 24 by a wire 25. The opposite or free end of the switch is connected by a wire 26 to a remotely placed alarm 21, the alarm being connected by a wire 28 with the source of current 24. Thus, when the mercury tube is supported in elevated position by the lever i8, the circuit through the motor is closed, causing operation of the stoker, while the circuit through the signal is opened. Upon operation of the stoker being aflected by an obstruction such as to cause a blowoii of valve l5 and releasing oi the switch, its downwardly tilted position causes the circuit to the motor to be broken and the circuit to the signal to be closed. This will call attention to the fact that the stoker is not operating and requires attention.

Other automatic controls may be electrically connected in the above described circuits as may be desired to include thermostatic controls and kindling controls in the usual manner and as is well understood in the art.

The invention claimed is:

1. In stoker mechanism, hydraulic pressure means for operating the stoker, an electric m0- tor to operate said pressure means, a relief valve for said pressure means, a switch in the circuit of said motor, a member operable by impact of pressure from said valve for operating said switch to deenergize said-motor, a signal, and a circuit including said signal and said switch, closed when said switch is moved 'to' motordeenergizing posi- 2. In stoker mechanism, hydraulic pressure means for operating the stoker, a motor to operate said pressure means, a relief valve for said pressure means, a signal, and a member operable by impact of pressure through said relief valve for rendering said motor inactive and to simul taneously operate said signal.

3. In stoker mechanism, hydraulic pressure means for operating the stoker, a motor to operate said pressure means, a switch in the circuit of said motor, a lever for operating said switch, a relief valve for said pressure means, means operable by impact of pressure from said valve for operating said lever, a signal, and a cit-1 cuit including said switch and said signal and,

closed when said lever has been operated by impact of pressure from said valve.

4. In an alarm device for stokers having a hydraulic power transmission including a pressure cylinder, the combination with a pressure release bypass valve communicating with said cylinder, of a remotely positioned electrically actuated signal element, a source of electric current in circuit with said element, a switch in said circult, means for supporting said switch in open circuit position, and a member associated with said means and valve for receiving the impact of fluid released from said valve to move said means in position to release said switch and permit it to move to circuit closing position.

5. In an alarm device for stokers having a hydraulic power transmission including a pressure cylinder, the combination with a pressure release bypass valve communicating with said cylinder, of a remotely positioned electrically actuated signal element, a source of electric current in circuit with said element, a switch in said circuit, means for supporting said switch in open circuit position, a member associated with said means and valve for receiving the impact of fluid released from said valve to move said means in position to release said switch and permit itto move to circuit closing position, and a plunger operatively associated with said switch for returning it to circuit breaking position.

6. In an alarm device for stokers having ahydraulic power transmission including a fluid pressure cylinder, the combination with a pressure release bypass valve communicating therewith, of a remotely positioned electrically actuated signal element, a source of electric current in circuit with said element, a switch in said circuit, an electric motor constituting the source of power for said transmission in circuit with said source and switch, a movable member normally engaging said switch to support it in sig nal circuit open and motor circuit closed position, and a cup connected with said movable member in position to be moved by the impact of fluid released from said valve to cause said member to release said switch and permit it to close the circuit through said signal and open the circuit through said motor.

7. In an alarm device ior stokers having a hydraulic power transmission including a fluid pressure cylinder, the combination wilih a pressure release bypass valve communicat ng therewith, of a remotely positioned electrically-actuated signal element, a source of electric current in circuit with said element, a switch in said circuit, an electric motor constituting the source of power for said transmission in circuit with said source and switch, a latch pivotally mounted on said transmission normally'engaglng said switch to support it in position wherein said alarm circuit is broken and said motor circuit is closed, a cup mounted on the pivotal mounting of said latch in position to be moved by the impact of fluid released from said valve to cause said latch to release said switch and permit it to move to close the circuit through said element and open the circuit through said motor, and a manually actuated plunger positioned to move said switch from its unlatched position to latched position for breaking the alarm circuit and closing the motor circuit.

JOHN ROLAND.

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