US1921217A - Safety device - Google Patents

Description

Aug. 8, 1933. I J. T. COGHILL 1,921,217

SAFETY DEVICE Filed Sept. 12, 1932 2 Sheets-Sheet 1 JAMES 7'. COGHILL A TORNEYS SAFETY DEVICE Filed Sept. 12, 1932 2 Sheets-Sheet 2 INVENTOQ= JAMES 7T COGH/LL v AT TOENEYS Patented Aug. 8, 1933 SAFETY DEVICE James T. Coghill, Hoosick Falls, N. Y., assignor to The Noble & Wood Machine Company, Hoosick Fails, N. Y., a Corporation of New York Application September 12, 1932 Serial No. 632,657

13 Claims.

My invention relates to safety devices and particularly to a means for automatically actuating a valve, sv itch, clutch mechanism or the like after the expiration of a predetermined interval of time following the failure to operate of certain mechanism with which the device may be associated. The invention is here illustrated and described in a form particularly designed and adapted for use in connection with felt conditioners used in the paper making art although it is to be understood that its use is not so limited.

In the paper making art an endless belt of felt is used to carry the web of paper during a portion of its travel through the paper making machine. These belts are made of extremely high grade wool and are long, wide, and very expensive. Furthermore, they are comparatively short lived. In the process of paper making the felt becomes impregnated with dirt, clay, size and other substances usually founder intentionally incorporated in the stuff. As the felt becomes impregnated its absorptive properties are reduced and to eliminate this diniculty and increase the useful life of the felt, it is usual to employ conditioners. The usual form of conditioner includes one or more nozzles which are reciprocated transversely back and forth across the felt and through which jets of water at high pressure are directed against the back surface of the felt to blow out the dirt etc., and raise the nap of the felt. The mechanism which reciprocates the jets of water back and forth across the felt frequently fails to operate, in which event unless an attendant is present to start the jets moving or to shut off the water, the continued application of the jets in one zone will quickly cause a seam to develop and ruin the felt. In some cases, with fine felts, such as on tissue machines, the felt may be cut entirely in two.

The principal object of my invention, therefore, is to provide a safety device which will function automatically to stop certain parts of a mechanism after the lapse of a predetermined in erval following the failure of other parts to operate. As applied in the paper making art, for example, it may be used with a felt conditioner to shut off the supply of water to the jets after the lapse of a predetermined interval of time following the failure of the jet reciprocating mechanism to function.

My invention, therefore, includes the novel elements and the arrangements and combinations thereof described below and illustrated in the accompanying drawings in which-- Fig. l is a front View of my device with. certain parts removed to show details of construction;

Fig. 2 is a side elevation view, partially in section;

Fig. 3 is a typical wiring diagram showing certain elements of my device in one position; Fig. 4 is a diagram similar to Fig. 3 showing the same elements of my device as illustrated in Fig. 3 but in somewhat different relative position; and

Fig. 5 is a fragmentary perspective view showing, in a more or less typical manner, a felt conditioner with elements of my device associated therewith.

Referring now to the drawings, my device includes a casing, 1, in which is enclosed most of the mechanism of my device and which said casing is provided with a suitable supporting base, 2, 3, is the water supply pipejto the end, 4, of which is secured a suitable conductor leading to the nozzle of the felt conditioner. Water flows out of the pipe in the direction shown by the arrow, 5, and into the pipe as shown by the arrow, 6, 9 represents, generally, a standard swing gate valve provided with a gate or closure element, 10, mounted on a shaft, 11. The valve actuating lever, 12, is secured to a squared portion, l3, of the valve shaft so that the valve may be opened or closed by moving the lever, 12, up and down respectively. When the lever is in the position, 12, shown in Fig. 1 the closure element is in the position, it), and the valve is open, but when the lever is in the position indicated by the dash and dot lines, 12', the closure element is in the position, and the flow of water to the conditioner nozzle is shut off.

Pivotally mounted to the casing at 131 is the crank, 14, having an approximately horizontal arm provided with a weight, 15, at the extremity thereof. The horizontal arm, 16, of the crank, 14, is provided with a projection, 17, which engages or latches with a projection, 18, on the lever, 12, when the lever, 12, is in the position shown in the solid lines in Fig. 1. That is to say, when the lever is raised so that the valve is open it will be held in that position by means of the interengagement of the projections, 17 and 18.

Freely and rotatively mounted on a suitable bearing is the toothed wheel, 19, to which is secured a weight, 20, carrying the projecting pin, 21, so positioned that when the wheel, 19, is rotated upon its bearing the pin willcontact with the offset portion, 22, of the crank, 14, and move the crank, 14, to position, 14'. When the crank, 14, is moved to the position 14' the horizontal arm, 16, is raised to the position 16, shown in dotted lines in Fig. 1 thus withdrawing the projection, 17, from engagement with the projection, 18, on the lever, 12. This will permit the lever to drop to the position 12' and close the water valve.

Pivotally mounted at 23 for limited rotative movement in a vertical plane is a self-starting synchronous motor, 24, of the Telechron type, the shaft of which carries, at its extremity, a pinion, 25, normally in mesh with the toothed wheel, 19. The motor, 24, is also supported on the pinion side by an element, 26, secured thereto and to the armature, 27, of a solenoid magnet, 28, by means of a link, 29. When the solenoid is energized, the armature, 27, is lifted to position 27 shown in the dotted lines in Fig. 2. This upward movement of the armature rotates the synchronous motor slightly about its pivotal mounting, 23, to the position 24' and this movement lifts the pinion, 25, to the position 25 and out of engagement with the toothed wheel, 19. The motor is designed to rotate slowly in the direction of the arrow shown in Fig. 1 and at a definite number of revolutions per minute.

From the foregoing it will be apparent that when current is supplied to the motor, 24, the toothed wheel, 19, will be rotated slowly in the direction of the arrow shown thereon in Fig. 1. The weight, 20, with the pin, 21, will be raised upwardly toward the offset end, 22, of the crank, 14, and the pin, 21, will eventually contact with the offset end, 22, forcing it to the left, thus raising the latch, 17, holding the lever, 12, in the position shown in the solid lines in Fig. 1. The lever, 12, will then fall to the position 12 closing the valve. If the pinion, 25, is raised out of engagement with the toothed gear, 19, by energizing the solenoid, 28, before the pin, 21, has reached the end, 22, of the crank, 14, it will be apparent that the weight, 20, will cause the toothed wheel, 19, to rotate in the opposite direction from the arrow shown thereon until the pin, 21, comes in contact with'the projecting element, 31. That is to say, the pin, 21, will return to its starting point or the position shown in Fig. 1. i

In Figs. 1 and 2 the projecting element, 31, is shown in vertical position, but this projecting element is secured to the shaft, 32, extending through a boss, 33, in the casing as best shown in Fig. 2, and which is provided at the back with a lock nut, 34, and a pointer, '35. By loosening the lock nut, 34, and turning the shaft, 32, the projecting element, 31, may be turned so that the starting point of its 'movement is advanced. In other words, the angular distance through which the toothed wheel must turn between its starting position and its latch actuating position may be varied. In this way, as will be more fully explained later, the interval of time which elapses between the shutting off of the water supply and the failure to operate of the reciprocating mechanism can be adjusted to conform to different lengths of felts or different felt conditioner speeds. In Figs. 3 and 4 I have shown in a more or less typical way the action of my safety device although for clearness I have moved the motor, 24, to one side of the pinion, 25.

In Figs. 3 and 4 the parts, shown more in detail in Figs. 1 and 2, "are represented by the same numbers. 36 and 3'7 represent busses or wires carrying alternating current, and the supply thereof to the motor, 24, the solenoid, 28, and other parts of my apparatus to be hereinafter described is controlled by a mercury switch within a handle, 38, of lever, 12. This switch may be of the Mercoid type in which 39 represents mercury forming contact between the two elements, 40 and 41, when the lever is in the position shown in Fig. 3 or in the position shown in solid lines in Fig. 1. When the lever is in the position shown in Fig. 3 current flows constantly to the motor, 24. Interposed in the circuit leading to the solenoid, 28, is a second mercury switch, 42, which is pivotally mounted at 43 (see Fig. 5). In this switch, 44, represents the mercury which makes contact between the elements, 45 and 46, when the switch, 42, is tilted to the position shown in Fig. 3. The normal position of the switch, 42, is as shown in Fig. 4. That is to say, the switch is normally open so that no current is flowing through the solenoid.

Referring now to Fig. 5 the felt is represented by 47 and one of the reciprocating conditioner nozzles is shown at 48. Secured to this nozzle is a projecting element, 49, designed to hit the depending portion, 56, of the switch, 42, every time the nozzle, 48, passes and tilt the switch about its pivotal mounting, 43, to contact making position. In other words, if the reciprocating movement of the nozzle, 48, ceases, the switch, 42, will remain in the position shown in Fig. 4 and will never be tilted to the contact making position shown in Fig. 3.

In operating, the lever, 12, is raised from the position 12, shown in dotted lines in Fig. 1, to the position indicated by the solid lines. This closes the switch, 38, and starts the motor, 24, running, the lever, 12, being held in circuit closing position by the inter-engagement of the latch elements, 17 and 18. As the motor operates, the pin, 21, will be gradually turned towards the end, 22, of the crank, 14, but since this movement of the gear, 19, is comparatively slow, 120 the pin, 21, will be only part way on its travel toward the end, 22, when the pivotally mounted switch, 42, is tilted by the projecting element, 49. When this happens, the switch, 42, is closed and the solenoid is energized, thereby raising the pinion, 25, out of engagement with the teeth on wheel, 19, as shown in Fig. 3. This will cause the weight, 20, on wheel, 19, to carry the pin, 21, back to its starting position as shown in Figs. 1 and 3. If, for any reason, the nozzles of the conditioner cease to reciprocate so that the switch, 42, is not periodically closed, the pin, 21, will eventually be carried to the position 21' or in contact with the end, 22, of crank, 14, and push it to the position 22', as shown in Figs. 135 1 and 4. This will raise the latch lug, 17, out of engagement with the lug, 18, and the lever, 12, will fall back to the position 12' shown in Fig. 4, thus shutting off the water to the nozzles and also breaking the circuit through the motor,

In order to prevent overload on the motor, 24, and to prevent the pin, 21, from pushing the end, 22, of the crank, 1.4, beyond the position 22 shown in Fig. 4, several of the teeth are removed from the wheel, 19, in the zone, 51, as shown in Figs. 1, 3 and 4. Inasmuch as there are no teeth on the wheel, 19, in the zone, 51, the motor, 24, will continue to turn but will effect no further turning of the pin beyond the po- 81131011 21'. 100

Different mills operate their felt conditioners at different speeds. For example, a mill which uses a two-minute cycle for its felt conditioner would wish to have the nozzle water shut off within about 2 minutes after the conditioner stopped. Likewise a mill on a longer or shorter cycle will wish to regulate this time interval to suit conditions. This may readily be done, as pointed out above, by loosening the lock nut, 34, and moving the projecting stop element, .31, upwardly so that the angular travel of the pin, 21, between its starting point and its latch-releasing position is reduced. Since the synchronous motor operates at constant speed, this adjustment of the stop element, 31, will accurately regulate the interval of time which elapses between 21. stoppage of the nozzle reciprocating movement and the shutting off of the water.

One type of conditioner in common use is provided with a suction nozzle combined with the water nozzle which is particularly damaging to the felt whenever the nozzle stops, since the vacuum creates a bulge in the felt which cannot be worked out. In accordance with my invention an auxiliary diaphragm valve is provided in the nozzle line which turns off the suction valve whenever the nozzle water is shut off.

While I have illustrated and described my invention as applied to a felt conditioner, it is perfectly obvious that it may be applied to any mechanism where it is desired to stop one element thereof after the lapse of a predetermined interval of time following the stoppage of a second element thereof. Therefore, it is to be understood that the drawings are illustrative of only one of the many applications of my invention; that the words which I have used are words of description rather than of limitation; and that changes in its structure and its application may be made in the appended claims without departing from the true scope of my invention in its broader aspects.

What I claim is- 1. In a safety device of the character de scribed, the combination with a felt conditioner provided with a water nozzle which is reciprocated across the felt, of a valve for shutting off the supply of water thereto, and means responsive to a stoppage in the movement of said nozzle for automatically closing said valve.

2. In a safety device of the character described, the combination with a felt conditioner provided with a water nozzle which is reciprocated across the felt, of a valve for shutting off the supply of water thereto, and means for automatically closing said valve after an interval of time following a stoppage in movement of said nozzle.

3. In a safety device of the character described, the combination with a felt conditioner provided with a water nozzle which is reciprocated across the felt, of a valve for shutting off the supply of water thereto, means for automatically closing said valve following a stoppage in the movement of said nozzle, and means for regulating the interval of time elapsing between the stoppage of the nozzle and the shutting off of the water.

4. In a felt conditioner, the combination with a movable nozzle for spraying the felt, of means including a valve for supplying water to said nozzle, and means responsive to a stoppage in the movement of the nozzle for closing said valve.

5. In a device for stopping one element of a mechanism when a second element thereof fails to operate, the combination with means for actuating a stop mechanism, said means being normally in stop-mechanism position, of a latch for holding said means in mechanismmperating position, means for releasing said stop-mechanism actuating means, means for moving said releasing means progressively and at a uniform rate of speed from a starting point, and means periodically actuated by a movement of said second element for eifecting a return to its starting point of said releasing means.

6. In a device for stopping one element ofa mechanism when a second element fails to operate, the combination with means for actuating a stop mechanism, said means being normally in stop mechanism position, of a latch for holding said means in mechanism operating position, means for releasing said latch, means for moving said last mentioned means at a uniform rate of speed from a starting point to latch-releasing position, means actuated by the movement of the second element for periodically effecting a return to its starting point of the latch releasing means, and means for varying the time required for the latch releasing means to move from its starting point to latch releasing position.

7. In a device for stopping one element of mechanism when a second element thereof fails to operate, the combination with a lever for actuating a stop mechanism, said lever being normally in a stop-mechanism position, of a latch for holding said lever in mechanism-opera ating position, latch-releasing means, means for progressively moving said last mentioned means from a starting point to latch releasing position, a synchronous motor for moving said latch releasing means at a uniform rate of speed, and means responsive to the movement of said second element for periodically effecting a return to its starting point of the latch-releasing means before it reaches its latch releasing position.

8.111 a safety device of the character described, the combination with a felt-conditioner provided with a nozzle which is reciprocated across the felt, of means including a valve for supplying water thereto, means for actuating said valve, said last mentioned means being normally in valve-closed position, a latch for holding said valve actuating means in valve-open position, means for releasing said latch, means for moving said latch releasing means progressively and at a uniform rate of speed from a starting point to latch-releasing position, and means responsive to the movement of said nozzle for periodically returning the latch releasing means to its starting point.

9. The device set forth in claim 8'together with means for varying the time required for the latch-releasing means to move from its starting point to latch-releasing position.

10. In combination, a movable pervious sheet, a felt nozzle, means comprising a valve for supplying liquid thereto, means for moving said nozzle back and forth across said sheet, and means responsive to the stoppage of movement of said nozzle for closing said valve.

11. In combination, a movable pervious sheet, a felt nozzle, means comprising a valve for supplying liquid thereto, means for moving said nozzle back and forth across said sheet, means for opening said valve and means responsive to the stoppage of movement of said nozzle for closing said valve.

12. In combination, a movable pervious sheet, a felt nozzle, means comprising a valve for supplying liquid thereto, means for moving said nozzle back and forth across said sheet, manually operable means for opening said valve, and means responsive to the stoppage of movement of said nozzle for closing said valve.

13. In combination, a'felt conditioner pro-

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