US2029349A - Automatic control mechanism - Google Patents

Description

Feb. 4, 1936. K WA NE 2,029,349

AUTOMATIC CONTROL MECHANI SM Filed Feb. 23, 1932 Patented Feb. 4, 1936 UNITED STATES PATENT OFFICE signor, by

mesne assignments, to

Magnesium Development Corporation, Newark, N. J a corporation of Delaware Application February 2 In G 5 Claims.

The present invention relates to an electricallyoperated automatic control mechanism, particularly for use in connection with automaticallycontrolled die-casting apparatus.

In automatically-controlled mechanisms it is frequently desired to interrupt the operation of the entire device for a definite interval during each working cycle, and it is an object of the present invention to provide a control mechanism which will cause such an interruption to be performed automatically for a period which is independent of the duration of the working cycle proper and which may be adjusted to suit various operating conditions.

The invention will be described hereinafter with reference to its application in connection with die-casting apparatus. It will be seen, however, that it is by no means limited to such ap plication, but may be applied equally well, with changes obviously occurring to the skilled technician, in all instances in which the aforementioned object is to be attained.

In the production of castings in die-casting apparatus it is often necessary to vary the solidification period, that is to say, the interval of inaction between the termination of the moldcharging step and the step of opening the mold sections, since this period varies with castings of varying dimensions and shape. At the same time, it is found desirable, especially in automaticallyoperated die-casting apparatus, to also insure the maintenance of this interruption in the working cycle, or'period of rest, by mechanical .means, and further to be able to conveniently regulate the duration of the period of rest to suit the special features and characteristics of the various castings.

According to the present invention this problem is solved by incorporating in the control mechanism of the die-casting apparatus an adjustable, but otherwise automatic, electrically-actuated clutch, by means of which the drive of the machine is interrupted for an adjustable period of time. This is suitably effected by providing an electrically-operated clutch, coupling the drive shaft of theapparatus with the main control or operating shaft, and means for shutting off the current supply to said clutch, and simultaneously, in a shunt circuit, setting a contact member in time-controlled motion, which restores the supply of the current for operating the clutch at the end of an adjustable interval.

In order to more clearly understand the nature of this invention, reference is made to the accompanying drawing which diagrammatically 3, 1932, Serial N... 594,759

ermany February 25, 1931 illustrates, by way of example, a typical embodiment of the mechanism according to the principles of this invention, and in which:

Fig. 1 represents a view in front elevation of a mechanism embodying the principles of the invention;

Fig. 2 represents a view of the mechanism in side elevation, as viewed from the right of Fig. 1, portions of the apparatus being broken away and shown in section to more clearly show its mode of construction;

Fig. 3 represents a cross sectional view taken along the line III-III of Fig. 1,

Referring to the drawing, 41 represents a graduated dial in cooperative relationship with respect to a pointer b secured to the control shaft h of a die-casting machine or the like. As is well known to those versed in the art, the shaft h is adapted to control the various operations of an automatic mechanism during its working cycle, and in accordance with the invention the position of the pointer 12 secured to the shaft h. and rotating therewith, is indicative at all times of the state of the machine with reference to a complete working cycle. In the drawing pointer b is shown in its position during the idling period of the machine.

Anelectromagnetically-operated clutch g is provided for coupling the control shaft h with a main drive shaft 11, the shaft h being constructed in two sections connected together by means of a suitable coupling '2 and electrically insulated from each other by means of a suitable interposed plate of fiber (not shown) within the coupling i. An electrical contact k is mounted upon the shaft h, the purpose of which will be hereinafter understood.

The pointer b is provided with two sliding contact members In and be by means of which electrical connection may be established between a contact ring c or a clock mechanism 12 and the main supply leads L1 and L2, the pointer b being constructed from conducting material and in circuit with the lead L1 through the medium of the contact ring it mounted on shaft h. Another lever e is rotatably mounted on the shaft h and is in electrical contact therewith. This lever is provided with a contact member c1 and an abutment or stop e2, said lever being adapted to be moved either by the pointer I) through its engagement with the abutment e2 or by means of the electrical clock mechanism 11 which is set in motion at a moderate rate of speed in accordance with the desired interruption of the control shaft h during a working cycle. The clock dium of the ried forward with mechanism 11 is connected to the hub of lever e by means of a suitable gear transmission, 1, m. It will thus be seen that the lever e may be rotated with the pointer b and shaft h or may be separately rotated with respect to said shaft h by means of the clock mechanism (1.

The pivotal axis of the lever e is in continuous electrical connection with the pointer b, whereas the sliding contact member e1 on the under side of this lever establishes electrical connection with a control or adjustable lever ,f, the control lever being rotatably mounted on the shaft h and insulated therefrom as by means of a fiber bushing r or the like. The lever f is adjustable with respect to the contact ring c with which it is always in electrical connection through the mesliding contact member f2, the ring 0 being discontinuous in that it is provided with a gap 01.

In the operation of the control mechanism the contact ring 0 is adjusted on the dial a in such a manner that the sliding contact hi on the under side of the pointer b reaches the gap 01 in the contact ringc at the moment the die-casting process has proceeded to such an extent that the opening of the mold would follow as the next active operation in a working cycle. At this moment the electrical circuit, including the pointer b, ring 0, clutch g and leads L1 and L2 is broken and the current interrupted thereby, which action results in the disengagement of the electromagnetic clutch 9. That is, the control shaft h is disconnected from the operating shaft p. At the same time, however, the electrical circuit of the clock mechanism d is completed through the medium of the contact member 122 on the under side of pointer b coming in contact with the stationary contact member 173. The completion of this circuit sets the clock mecha-' nism din motion so that the lever e moves away from the pointer 17 and continues its course towards the right as viewed in Fig. 1. The period that elapses until. the contact e1 of this lever reaches the contact member f1 onthe control lever f may be varied at convenience by suitably adjusting the position of the lever ,f, and the resulting establishment of an electrical connection between e1 and f1 energizes the magnetic clutch 9 through the completion of the electrical circuit with the ring 0 at f2, thereby rotating theshaft h, which enables the-machine to resume its working cycle, the first function of which opens the mold. Rotation of the shaft h in performing a new working cycle moves the contact member In, of the pointer 21, into electrical connection with the contact ring 0 and at the same time breaks the electrical connection b2 be, which latter action stops the clock mechanism d, temporarily arresting the forward movement of the lever e. As the shaft h and pointer b continue to rotate, the pointer b engages the abutment es With the result that the aforementioned lever is again carthe pointer into the position shown in Fig. 1, at which point the gap 01 has been reached and the operation of shaft h is again interrupted.

v It will be understood from the previous discussion of the operation of the mechanism constituting this invention that during the rotation of the pointer 22 through the medium of shaft h, and

' during the interval of driving Contact of lever e by pointer b the clock mechanism 11 will be actuated or mechanically driven.- Interruption in the rotation of-pcinter b, on places the pointer in the other hand (Fig. 1), position tocomplete the electrical drive for the clock mechanism d, which arrangement electrically actuates the clock mechanism to drive the lever e independent of the rotation of shaft h.

It is to be understood that the electromagnetic clutch above described and the mechanism for controlling the same is not'restricted in its application to die-casting apparatus, and may be employed in all cases in which, during a number of periodically recurring operations, a pause of definite duration-which is adjusted according to circumstanceshas to be interposed.

I claim:

1. An automatic control mechanism comprising driving means, main operating means, a clutch adapted to couple said driving means with said main operating means, means for electrically actuating said clutch, means for shutting off the current supply to said clutch-actuating means when a predetermined position of said main operating means has been attained, a contact member adapted to perform a movement of predetermined speed and duration, electrically actuated means adapted to cause such movement, means for restoring the current supply for actuating the said clutch at the termination of the movement of said contact member, and means adapted to establish the current supply to said movement-causing means incidentally with the shutting off of the current supply to said clutchactuating means, said last-mentioned currentestablishing means being adapted to shut oif the current supply to said movement-causing means incidentally with the restoration of the current supply to said clutch-actuating means,

2. An automatic control mechanism comprising driving means, main operating means, a clutch adapted to couple said driving means with said main operating means, an electric circuit including a contact ring for electrically actuating said clutch, means in the form of a gap in the circumference'of said contact ring for shutting off the current supply to said clutch-actuating means when a predetermined position of the main operating means has been attained, a contact member adapted to perform a movement of predetermined speed and duration, an electrically actuated means adapted to cause such movement, means for restoring the current supply for actuating the said clutch at the termination of the movement of said contact member, and means adapted to establish the current supply to said movement-causing means incidentally with the shutting off of the current supply to said clutchactuating means, said last-mentioned currentestablishing means being adapted to shut ofi the current supply to said movement-causing means incidentally with the restoration of the current supply to said clutch-actuating means.

3. An automatic control mechanism comprising driving means, main operating means, a clutch adapted to couple said driving means with said main operating means, an electric circuit including a contact ring for electrically actuating said clutch, means in the form of a gap in the circumference of said contact ring for shutting oh the current supply to said clutch-actuating means when a predetermined position cf the main operating means has been attained, a contact member adapted to perform a movement of predetermined speed and duration, an electrically-operated clock mechanism for driving said 4. An automatic control mechanism comprising a driving shaft, a main operating shaft, a clutch adapted to couple said driving and main operating shafts, a pointer secured to said main operating shaft and rotated thereby, a contact ring, said pointer having a contact member in sliding contact with said contact ring, an elec-v trical circuit for actuating said clutch, said electrical circuit including the pointer and contact ring, means in the form of a gap in the circumference of said contact ring for interrupting said electrical circuit to disengage said clutch and stop said main operating shaft, a stationary contact member adjacent the gap in said contact ring, a lever arm mounted upon said main operating shaft and rotatably movable with respect thereto, an electrically-actuated clock mechanism for driving said lever arm, a shunt electric circuit including said pointer, said stationary contact member and said clock mechanism for actuating the clock mechanism, said pointer, when opposite the gap in said contact ring, being in electrical circuit with said stationary contact member and closing said shunt circuit, an adjustable member in electrical connection with said contact ring, a contact member disposed on said lever arm and adapted to make contact with said adjustable member, said contact between the lever arm contact member and adjustable member occurring at a predetermined interval following the interruption in said clutch-actuating electrical circuit, and said contact between the lever arm contact member and the adjustable member being adapted to restore the electrical circuit to said clutch-actuating means.

5. An automatic control mechanism comprising an electromagnetic clutch interposed a driving shaft and a control shaft, a stationary electrical conducting contact ring, an electrical conducting pointer secured to said control shaft and adapted to contact with said contact ring, an electrical circuit including said contact ring and pointer for energizing said clutch to normally maintain it engaged, a switch in the form of a gap in said contact ring for interrupting contact with said pointer to thereby open the clutch electrical circuit, means for maintaining said clutch electrical circuit open a definite predetermined interval, said means comprising a shunt electrical circuit including the pointer and a contact member, means for closing said shunt circuit on interrupted contact of the pointer and contact ring, a clock mechanism for driving said contact member, said clock mechanism being actuated electrically through the medium of said shunt circuit, and an adjustable member in electrical connection with said contact ring, said adjustable member being adapted to be contacted by said contact member, whereby said clock mechanism is deenergized and said clutch electrical circuit closed.

KARL FRIEDRICH WAGNER.

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