US2171114A - Delayed action switch - Google Patents

Description

1-1. w. JONES DELAY ACTION SWITCH Original Filed Oct 11, 1934 INVENTOR 8 w Y 0 E m w m R T A Mfm m Patented Aug. 29, 1939 PATENT OFFlCE DELAYED ACTION SWITCH Homer W. Jones, Westfield, N. J.,

assignor, by

mesne assignments, to Union Carbide and Carbon Corporation,

a. corporation of New York Application October 11, 1934, Serial No. 747,850 Renewed July 30, 1938 12 Claims.

This invention relates to a delayed action switch, and more particularly to a delayed action circuit breaker especially. adapted for use in an electric igniting circuit of the type in which ignition is produced by intermittent or occasional contact of two terminals of the circuit. The invention is especially useful in connection with the ignition of gases issuing from gas-delivering appliances, such as blowpipes, in its application to which the invention will be described.

In the operation of blowpipes and the like it is sometimes undesirable or inadvisable to employ a separate handlighter or a constantly burning flame for lighting the operating gas jet. At times, therefore, ignition of the gas jet has been effected by means of an electric spark between two terminals, of which the blowpipe tip is made one. A disadvantage of such an arrangement is that if the operator should permit contact between the terminals for any appreciable time, as by laying down the blowpipe on the work, which may form the other terminal, a continuous short circuit results which mayaifect disadvantageously the source of electromotive force which is used; as, for instance, overheating a. transformer or discharging a battery. Furthermore, when more than one blowpipe is used in the circuit and one of the blowpipes is permitted to remain in contact with the work, the remaining blowpipe lighters are rendered inoperative.

One object of the invention is to provide, in an electric igniting circuit, means whereby the circuit is closed only when actually needed. An-

other object is the provision in such a circuit 35' of means whereby a number of units may be ignited, as required, without affecting the ignition of other units in the circuit. A further object is the provision in such a circuit of means whereby ignition cannot be effected unintentionally. Other objects will become apparent upon consideration of the following specification.

The invention is illustrated by way of example in its application to a blowpipe igniting circuit in the accompanying drawing, in which:

Figure 1 is a semi-diagrammatic View of an apparatus constructed and arranged in accordance with the invention;

Figure 2 is a vertical mid-section through a circuit breaker for use in the igniting circuit; and

Figure 3 is a diagrammatic view of an igniting circuit for use with a plurality of blowpipes and a plurality of work pieces.

According to the present invention as applied to blowpipe ignition, a metallic part of a blowpipe is made one terminal of a circuit including a source of electromotive force, the metal work piece upon which the blowpipe is to operate is made the other terminal of the circuit, and a delayed-action time controlled circuit breaker is electrically connected in the circuit. Accordingly, the electric igniting circuit for the blowpipe is automatically broken after a predetermined time interval. Where desired, a plurality of blowpipes may be connected in parallel in the circuit, and a circuit breaker may be disposed in the branch circuit with each blowpipe. Referring now to the drawing and more particularly to Figure 1, it will be observed that there is shown an electric igniting circuit it], including a secondary coil H of a transformer I2. The voltage used in the circuit H1 is low, preferably between 2 and 20 volts, so as not to shock the operator, but is sufficiently high to force a substantial current, preferably between 5 and amperes, through the resistance of the circuit. Some other source of electromotive force, such as a storage or other battery having a sufficiently low voltage to avoid shocking the worker and a sufficiently low internal resistance to produce the necessary current intensity through the resistance of the complete circuit, may be employed in place of the coil H. A blowpipe l3 and a work piece 14 form the terminals of the circuit. The blowpipe I 3 has a source of fuel gas and a source of combustion supporting gas connected thereto. The source of fuel gas is here shown as a tube 15, the source of combustion supporting gas is illustrated as. a tube, 16, and both are connected to the blowpipe 13 in the usual manner. Valves 6? and iii are provided for controlling the flow of these gases through the blowpipe. A circuit breaker 29, described more particularly hereinafter, is connected in the circuit It between the transformer and the blowpipe, aconductor 2% serving to connect the secondary coil I l with the circuit breaker, and a second conductor 21, having a resistance 22 therein, connecting the circuit breaker to the blowpipe. The other end of the secondary coil l I is connected to the work piece 14 by a conductor 23, and it is shown as having a spring clip 24, to which the conductor 23 is attached, gripping the edge of the work piece. Obviously the work piece may be connected with the source of electromotive force by different means.

When necessary or desirable, a plurality of blowpipes may be connected to a single source of electromotive force and such an arrangement is illustrated in Figure 3. In this embodiment, the conductor 20 leads from the source of electromotive force (not shown) and branches into conductors 23', 20, 20, forming three parallel circuits in each of which a blowpipe I3 is connected forming the terminal thereof. A conductor 23 is connected to the other side of the source of electromotive force and is continued in three parallel branch conductors 23, 23, 23, connected to three work pieces H1, H5, I4, which form the circuit with each blowpipe.

The circuit breaker employed is a delayed-acafter a predetermined time interval of contact.

About three to four seconds usually is sufflcient to light a blowpipe under ordinary conditions.

One form of circuit breaker which may be em-f" ployed for this purpose is illustrated in Fig. 2. In this form of circuit breaker, the conductor 29 is connected to a binding post 23a on the circuit breaker, in electrical contact with a second binding post 2019, from which a conductor 25 leads through the circuit breaker casing to make electrical connection with a movable contact 25. A second movable contact 21 is electrically connected with a conductor 28 which leads to the winding of a solenoid 29 forming part of the circuit breaker I9. The movable contacts 26 and 21 are adapted to abut each other, thus closing the electric circuit between them. They are bent substantially in the form shown, but are slightly resilient to prevent breakage and to insure better contact. The conductor 2! is connected to the other end of the winding of the solenoid 23, passing out of the casing of the circuit breaker.

The movable contacts 26 and 21 are carried by and insulated from the arms of a toggle 38, which are mounted in the circuit breaker casing and pivotally connected by a pin. A' rod 3| is disposed centrally of the circuit breaker and carries a movable core 32 which is operably associated with the solenoid 29. It is to be noted that the pin connecting the arms of the toggle 3!! is not connected with the rod 3|. When the solenoid is energized the movable core 32 is pulled upwardly into the solenoid, thereby moving the rod 3! in the same direction and raising a flange or collar 31, which is connected to, or which forms a part of the rod 3|, until this flange or collar engages the toggle beneath the pin connecting its arms. The flange or collar 3! being pulled further in an upwardly direction moves the toggle upwardly through the central position of its arms. Thus, the contactscZB and 21 are separated and held apart breaking the circuit and preventing passage of current through the circuit breaker. A stationary core 33 within the solenoid assists this action; and a helical spring 34 bearing upon a stationary element 35 within the casing and upon an adjustable abutment 36 upon the rod 3| tends to oppose the upward movement of the movable core 32 and of the rod 3| with the flange 31. The toggle may be reset, with the contacts 26 and 2'l'again closing the circuit, by movement of a lever 38. The lever 38 may be an extension of one of the arms of the toggle 39 being pivoted as at 39 within the casing and extending through the casing to a handle it by means of which the toggle and,

with it the contacts 26 and 21, may be operated. The circuit breaker may also serve as an on and ofi switch.

As stated, the circuit breaker is a delayedaction circuit breaker, the circuit therethrough being broken automatically after the circuit has been continuously closed for the desired time interval. In the embodiment illustrated a dash pot 4| is provided for retarding the breaking of the circuit for the desired interval of time. The dash pot comprises a cylinder 42 disposed above the solenoid 29, a piston 43 movable in the cylinder and operably connected to the movable core other terminals and other branch circuits. -A 32. of the solenoid, and a needle valve mechanism circuit breaker I9 is connected inthebranch,

id for regulating the action of the dash pot. The piston 33 is connected with the movable core 32 by means of a hollow piston rod 15 having an opening d3 therein for admission of air. A ball Valve 5'! closes tightly the upper end of the piston rod G5 which extends through the piston 43 within the cylinder, the ball valve 4'? being held upon its seat by a helical spring 48. Thus, the piston 43 may move freely in a downwardly direction, air passing through the opening 46 into the interior of the piston rod and forcing the ball valve t? from its seat to enter the cylinder 42 as the piston descends. Upward movement of the piston however, will not cause passage of the fluid therein through the hollow piston rod 45' because of the action of the ball valve il. However, the needle valve mechanism 44 provides for discharge of fluid from the cylinder 42 as the piston 43 moves upwardly, in a manner which will now be explained.

A port Q9 is provided at the top of the cylinder 32 by a housing 58 fitted therein. The housing 5!? has openings 5| therein through which fluid passing throughthe port Q9 may escape. A needle valve 52, carried by a stem 53 having a threaded section 56 operable in the housing 5|], is adjustable by means of a knurled head 55. The rate at which fluid may pass through the port d9 may therefore be controlled by turning the knurled head and thereby adjusting the position of the needle valve 52. The rate of upward move ment of the piston 33, and therefore of the rod 3|, is governed by turning the knurled head 55. Consequently, the time taken for the contacts 26 and 27 to be separated may be easily regulated by means of the needle valve mechanism. Once the toggle 33 has attained its upward position with the contacts separated the circuit breaker willmaintain the circuit open until the handle G0 is pulled upward in order again to close the circuit. I In operation, the operator turns ,on the gases entering the blowpipe by means of the valves l1 and I8, closes the circuit through the circuit breaker by pulling up the handle 40 and then rubs the tip of the blowpipe l3 on the work piece l4. This produces sparks and heated particles of oxide which light the gases at the tip of the blowpipe; The flame is then adjusted by means of the valves H and i8, and the operator proceeds with his work.

Meantime the circuit breaker maintains a closed circuit therethrough unless the external circuit is closed continuously for the predetermined interval of time, passage of current through the solenoid 29 slightly raising the movable core 32 against the action of thehelical spring 3 3 as fluid escapes through the port 49. However, the moment the circuit is opened externally the action of the solenoid upon the movable core ceases and the helical spring 3 returns the rod 3i with the flange 3? to its original position. However, should the external circuit be closed for the predetermined time interval the flange 31 will move the toggle 30 and break the circuit through the circuit breaker. No current then passing through the circuit breaker, the helical spring 34 will draw the rod 3! downwardly until the flange 3'! assumes its original position but the circuit will then remain open until the circuit breaker is reset by hand, since the rod 3! and the flange 31 do not act to move the toggle 3d downwardly. If, for any reason, the blowpipe gases are shut off and it is desired again to light the blowpipe for continuation of the work, the circuit breaker is reset by hand by pulling upwardly the handle 4%! and the work may be continued. If the external circuit has not been closed for the predetermined time interval there will of course, be no occasion for resetting the circuit breaker as the circuit therethrough will not have been broken.

The same procedure is followed where a plurality of blowpipes is employed, and because of the action of the circuit breakers any operation or misuse of one blowpipe will not interfere with ignition of the others.

From the foregoing description it will be apparent that the invention provides, in an electric igniting circuit, a delayed action switch whereby the circuit is broken after being closed for a predetermined time interval, and whereby the source of electromotive force cannot be damaged or discharged by continued contact of the terminals of the circuit. It will be further evident that, in circuits employing circuit breakers constructed in accordance with the invention, a plurality of igniting units may be included in the circuit and contact between the terminals of one unit will not affect ignition of the other units in the circuit. The circuit breaker is s mple, rugged, easily operated and easily maintained.

The forms here illustrated and described are presented merely to indicate how the invention may be applied. Other forms, differing in detail but not in principle from those here set forth, will readily suggest themselves to those skilled in the art.

I claim:

1. A delayed-action circuit-breaker comprising a solenoid, a movable core operably associated with said solenoid, an electric circuit in series with said solenoid and including resilient contact members for making and breaking said circuit, a toggle carrying said contact members operated by said movable core to make and break said circuit quickly at a point in the movement of said core, a dash pot having a piston rigidly connected to said movable core, and a needle valve mechanism for regulating the action of said dash pot.

2. In a circuit breaker, the combination of a toggle mechanism comprising a pair of pivotallyconnected arms; an electric circuit including a pair of contacts, one mounted on each of said arms; and delayed-action means, including a solenoid coil in said circuit, adapted to actuate automatically said toggle mechanism to separate said contacts and open said circuit.

3. A circuit breaker comprising, in combination, a pair of cooperating and relatively movable contacts; a solenoid in circuit with said contacts; mechanism operable either to move said contacts into engagement and close said circuit or to separate said contacts and open said circuit; a device for actuating said mechanism, said device being movable in one of two opposite directions by said solenoid when the latter is energized, to actuate said mechanism to separate said contacts and open said circuit; and means operable when said contacts are separated and said solenoid becomes de-energized for moving said device independently of said mechanism and in a reverse direction and to its initial position, thereby leaving said contacts separated and said circuit open.

l. A circuit breaker as claimed in claim 3, in which said last-named means comprises a resilient means also acting to retard the separation of said contacts.

5. A circuit breaker as claimed in claim 3, in which said device includes a member operable to engage and actuate said mechanism to separate said contacts upon movement of said device in one direction and to limit movement of said device in the reverse direction.

6. A circuit breaker as claimed in claim 3, including means independent of said device for actuating said mechanism in one direction to separate said contacts and in a different direction to move said contacts into engagement.

'7. A circuit breaker as claimed in claim 3, in combination with means operable to retard the movement of said device when said solenoid is energized.

8. A circuit breaker as claimed in claim 3, in combination with means operable to retard the movement of said device when said solenoid is energized; and mechanism for adjustably controlling the action of said retarding means.

9. A circuit breaker as claimed in claim 3, in which said device comprises a movable core for said solenoid; and a fixed core is associated with said solenoid to assist the action of said movable core when said solenoid is energized.

10. A circuit breaker as claimed in claim 3, in which said mechanism comprises a pair of toggle arms; said contacts are severally carried by said toggle arms; and said device comprises a movable core for said solenoid and a collar operatively connected to said core and adapted to actuate said toggle arms.

11. A circuit breaker comprising, in combination, a toggle having two arms; a contact mounted on each arm of said toggle, such contacts being adapted to abut each other in one position of said toggle and to separate in the other position thereof; automatic means operatively associated with said toggle for moving the same to one position only; and manual means operatively associated with said toggle for moving the same to either position.

12. A switch comprising, in combination, a pair of arms pivotally interconnected to form a toggle; a spring secured to each arm and having a free end substantially perpendicular to such arm; an electrical contact on the free end of each spring; and means for operating said toggle to move said contacts into and out of operative engagement with each other.

HOMER W. JONES.

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