US1950114A - Timing control system - Google Patents

Description

March 6, 1934. s. A. KOHOUT TIMING coN RdL SYSTEM Filed Sept. 1, 1932 3 Sheets-Sheet l 7106721 07" 576 Q. ffo/zouz Gefor WWW j March 6, 1934. G. A. KOHOUT ,950, 14

TIMING CONTROL SYSTEM Filed Sept. 1, 1932 5 Sheets-Sheet 2 ii m frzvelzi or George G. fl bkouf March 6, 1934. G. 'A. KQHQUT 1,950,114

TIMING CONTROL SYSTEM Filefd Sept. 1, 1932 3 Sheets-Sheet 3 Patented Mar. 6, 1934 UNITED STATES PATENT OFFICE Claims.

My invention relates to timing control systems adapted to periodically cause the actuation of an operating mechanism.

It is the purpose of my invention to provide a system of this character in which the timing control mechanism is automatically rewound and reset by the operating mechanism or its drive mechanism so that no auxiliary or extra equipment or supervision is needed.

More specifically, it is the purpose of my invention to provide a timing control mechanism for furnaces whereby the fuel feed and draft devices may be periodically caused to operate sufliciently to maintain the fire in the furnace in the proper condition even during the period when the normal furnace controls, such as the pressure controls on the boilers and the like, are in position to prevent the fuel feed from acting.

I will describe the preferred form of my in- 29 vention by reference to the accompanying drawings wherein- Fig. 1 is an assembly view showing a furnace equipped with my control mechanism;

Fig. 2 is an enlarged side view of the timing unit;

Fig. 3 is a view of a portion of the furnace operating mechanism;

Fig. 4 is a front view of the same mechanism with the cover removed;

Fig. 5 is a side view of the timing mechanism taken from the opposite side through that shown in Fig. 2;

Figs. 6 and 7 are detail views of the timing mechanism.

Referring now in detail to the drawings, in Fig. 1, I show the front of a furnace 10 which furnace has the stoke-r grates 11 for feeding fuel downwardly along the grates and has at 12 a damper in the stack to control the draft of the furnace by regulating the escape of the gaseous products of combustion. This furnace is of the same construction as that shown in my prior copending applications Serial No. 357,703, filed Apr. 24, 1929, Patent No. 1,917,375, July 11, 1933, for Automatic stoker, and Serial No. 455,715, filed May 26, 1930, Patent No. 1,875,616, filed Sept. 6, 1932, for Damper regulator, although of course the invention is applicable to other types of furnaces and to equipment other than furnaces.

As described in my prior application Serial No. 455,715, the damper 12 is controlled by the weight 13 in conjunction with the motor 14 which operates the fuel feeding mechanism so as partially to close the damper after the fuel feeding has stopped. This control is accomplished through the medium of a rock shaft 15 driven from the crank 16 which is suitably operated from the motor 14. The rock shaft, as shown in my prior application, is connected to the grates 11 by means of the link 17 and crank 18 so that, by 6 rocking the shaft 15, the grates may also be rocked to feed fuel toward the back of the furnace. The lever 19 connects the crank 16 to the shaft 15, and this lever 19 also has an extension 20 which connects to the link 21 by means of 'a pin 22 sliding in the slot 23. Also, moving with the lever 19 is an operating pin 24 which oper ates a switch at 25 at one end of the stroke of the lever 19 to open the switch. The switch 25, as will be hereinafter pointed out, controls the circuit of the motor 14 so as to make the motor stop with the grates 11 and the lever 19 in the same position each time it stops. The structure so far described is substantially the same as that shown in my prior applications.

Also, as shown in my prior application Serial No. 455,715, the link 21 controls a lever 26 so as to cause this lever 26 to stay in its downward position so long as the fuel feeding means and the motor 14 are operating but allows the lever 26 to rise when the motor stops in a manner which will be more fully described hereinafter. The lever 26 is connected to the bar 27 which is supported on the flexible cable 28 that in turn is connected to the'lever arm 29 that operates the damper 12. That is, when lever 26 is down, the damper is moved toward open position, but, when lever 26 rises-the weight 13 pulls the flexible lead 28 up and moves the damper toward closed position. The position of the damper may, of course, be adjusted by stopping the lever 26 in any one of the openings such as 30 in the bar 27. Lever 26 is fixed on shaft 33 which is journalled in casing 31.

The mechanism by means of which link 21 controls the position of lever 26 is housed in the casing 31 which mechanism is shown most clearly in Figs. 3 and 4. Link 21 is secured at its upper end to a lever arm 32 pivotally mounted on the shaft 33 which extends transversely through the casing 31. This arm 32 has at its other end a link 34 connected to the piston rod 35 of a dash pct 36. The arm 26 has the extension 42 which is connected to dash pct 36' in the same manner as arm 32 is connected to dash pct 36. This structure is shown and described fully in my copending application so the details of its operation will not be described herein.

Briefly, the operation, however, is as follows:

As the arm 20 of lever 19 moves up and down to engage the notch at 62.

during the rocking of the shaft 15, it naturally tends to move link 21, and, when the pin 22 hits the bottom of the slot 23, link 21 is pulled down thus moving the lever 32 in a clockwise direction and pulling up on the piston rod 35. On the rocking of the arm. 20 upwardly on the return stroke, pin 22 slides in the slot 23 and thus does not tend to move link 21 upwardly. Lever arm 32 has a lip at 36 which fits over the lever 26 and pulls lever 26 down with the lever 32 at starting into the position shown in Fig. 3. A latch 3'7 carried by lever 26 then en: gages the catch 38 and holds the lever 26 down until the locking mechanism indicated generally by the numeral 39 is released by the upward movement of lever arm 32 and its depending releasing member 40. When the catch 38 is released by this latch mechanism, the lever 26 is caused to move upwardly by means of the weight 13 on the damper 12. Dash pot 36 retards the rising of 26 and opposes turning of shaft 33 by'spring 44. Thus, so long as the motor is operating, the arm 32 is being drawn down once for each movement of the shaft 15 so as to position the lever 26, and, unless the lever 32 moves upwardly sufiicient to release the catch 38, lever 26 remains in its lowered position. Shaft 33 extends through the casing 31 and is connected by means of a crank arm 43 (see Fig. 4) to a spring 44, and this spring 44 normally tends to turn shaft 33 in a counterclockwise direction in opposition to the pull of the link 21 on the lever 32.

Referring now more particularly to Figs. 2,

. 4, and 5, the shaft 33 at its end opposite the crank 43 has a depending arm 45 which connects by means of a link 46 to a similar arm 4'7 mounted on the shaft 48 of the timing mechanism. Shaft 48 extends into the casing of the timing mechanism and has fixed thereto within the casing a lever arm 49 which arm has a lateral projection 50 engaging the switch arm 51. Switch arm 51 controls a bridging contact 52 by means of the pin 53 working in slot 54. Spring 55 causes the bridging contact to snap over when dead center is passed. 1

This switch mechanism is a well known commercial type of switch, and for our purpose it is sufiicient to say that movement of lever arm 51 in a clockwise direction opens the switch while movement of the arm 51 back to the position shown in Fig. 5 closes the switch.

Arm 51 is connected by a link 56 to the lever 57 of the timing mechanism. This lever is pivoted on a shaft 58 and carries at its end opposite the link 56 a dog 59 which cooperates with the cam 60 in the following manner: I

As lever 51 is moved in a clockwise direction by the projection 50, the link 56 rocks the lever 57 and moves the dog 59 in a clockwise direction rmtil the hooked end 61 thereof hooks over the notch 62 on cam 60. The roller 63 passes over the trip arm 64 and thus enables the hooked end 61 As the lever arm 57 is moved clockwise, it also winds the spring 65 of the clock mechanism which clock mechanism drives the cam 60 and with it the lever 5'7 in a counterclockwise direction so as to eventually cause the lever 63 to ride upon the trip arm 64 and thus release the lever 5'7 so that it may return to the position shown in Fig. '7.

This timing mechanism is with'the exception of the addition of the winding means also a well known time switch structure, and the details move the lever arm 49 as .switch at the bridging contact 52.

thereof are not claimed to be novel in the present case.

The trip arm 64 may be set, as for example, by lever 66 which is operated by means of an arm 6'7 on the inner end of shaft 68 and a finger piece 69 on the outside of the casing.

From the foregoing description, it will be seen that the rocking of shaft 33 by the pulling down of lever 26 to which it is secured moves the link 46 to the left as shown in Fig. 2 to cause lever arm 47 to rotate shaft 48 in such a fashion as to shown in Fig. 5 in a clockwise direction, thus opening the Also, this motion rewinds spring 65 through the medium of the link 56 and the lever arm 57 and resets the timing mechanism with the hook 61 engaged in the notch 62'. This starts the timing mechanism in operation, and the clock work allows the cam 60 and lever 57 to rotate slowly in a counterclockwise direction sothat after a predetermined lapse of time the trip arm 64 will trip the lever 57 and let it return to the position shown in Fig. '7 which again closes the switch 52.

. Switch 52 controls the circuit for the motor 14 in a manner which will now be described.

Referring now directly to Fig. l, the power leads for the motor are shown at '70 and '71 and are connected to the motor through a switch '72 that is operated by means of a relay coil '73. This coil '73 may be energized by closing the switch 74 which may be a manual or a pressure or a temperature operated switch as desired. Also, the coil '73 will be energized to close the switch circuit whenever the contacts of the limit switch 25 are closed, but will be deenergized to open the motor circuit when both switch '74 and the contacts of switch 25 are open. This is accomplished by connecting the leads '75 and '76 of the switch '74 in parallel with the leads '7'7 and '78 of the limit switch 25 so that when either 25 or '74 is closed the relay coil '73 is energized.

Now in order to complete the control by the timing mechanism just described, I connect this timing mechanism by means of the leads '79 and (see Figs. 1 and 5) in parallel with switch 25 and '74 so that even though switches 25 and '74 are both open, the closing of the bridging contact 52 of the timing switch will complete a circuit through this switch for the relay coil "13 and thus close the motor circuit to start the stoker grates. Immediately upon the starting of the stoker grates, the link 21 is, of course, pulled down by the lever 19 and pulls with it arm 32 and lever 26 to open the damper. Simultaneously with this motion, shaft 33 is turned so as to wind the timing mechanism through the medium of the lever 51, link .56, and lever 57. This winding of the timing mechanism insures operation of the timing mechanism again when the furnace stops for the predetermined time set on the clockwork of the timing mechanism. Pulling arm 51 in a clockwise direction as shown in Fig. 5 breaks the motor circuit between the leads '79 and 80, but, before this is done, the arm 19 has moved the pin 24 away from the switch 25 and allows the contacts of this switch to close. Consequently, the rock shaft 15 continues to swing through a complete cycle until it brings pin 24 back against the button on the switch 25 to open the motor circuit and stop the grates in the proper position. Thereafter, link 21 is raised by lever 32, and the raising of lever 32 by means of the spring turning shaft 33 releases the catch holding lever 26 down and allows this lever to rise which thereupon closes the damper. The turning of shaft 33 also releases the clockwork which during the operation of the fuel feeding motor is held out of operation by means of arm 49 on shaft 48.

Arm 49 when the motor starts pulls lever 51 to the right as shown in Fig. 5 and rewinds the clock mechanism. Then as long as the shaft 33 is held by lever arm 26 against turning in response to the pull of spring 44, the arm 49 prevents the clockwork from starting. It is only when 33 is released and returns slowly due to its dashpot 36 that the clockwork is allowed to start. Therefore, so long as the fuel feeding is operating steadily as when switch 74 is closed, the timing mechanism is at rest and does not interfere at all with the furnace operation. When the furnace is left idle and needs only an occasional feeding of fuel down the grates to keep it going, then the timing mechanism operates and switch 74 is open.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

l. A system of the character described for periodically starting and stopping operating mechanism having in combination a motor to drive said mechanism, a clockwork, a switch controlled by the clockwork to periodically close the motor circuit and start the mechanism, and means connecting the mechanism and clockwork to rewind the clockwork when the mechanism operates, said mechanism having means to prevent the clockwork starting until the mechanism stops.

2. A system of the character described for periodically starting and stopping operating mechanism having in combination a motor to drive said mechanism, a clockwork, a switch controlled by the clockwork to periodically close the motor circuit and start the mechanism, and means actuated by said mechanism to thereafter open the motor circuit and stop the mechanism, said mechanism having means to prevent the clockwork starting until the mechanism stops.

3. A system of the character described for periodically starting and stopping operating mechanism having in combination drive means for said mechanism, control means including a clockwork to periodically start said drive means, means actuated by said drive means to thereupon rewind the clockwork and reset said control means, and means on said operating mechanism to stop the drive means after the control means has been reset, said operating mechanism also having means to prevent the clockwork starting until the mechanism stops.

4. In a furnace, the combination of fuel feeding mechanism, a damper means controlled by the fuel feed mechanism for maintaining said damper open while the fuel feeding mechanism is operating, means to impart closing movement to said damper after the fuel feeding means stops, and a clockwork control started by the closing of the damper to again start the fuel feed mechanism after a predetermined time.

5. In a furnace, the combination of fuel feeding mechanism, a damper means controlled by the fuel feed mechanism for maintaining said damper open while the fuel feeding mechanism is operating, means to impart closing movement to said damper after the fuel feeding means stops, and a clockwork control started by the closing of the damper to again start the fuel feed mechanism after a predetermined time, said mechanism having connections to said clockwork control to rewind and reset it each time the mechanism is started.

GEORGE A. KOHOUT.

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