US1757922A - Magnetic stepping motor - Google Patents

Description

May 6, 1930. E. QUARTIER 1,757,922

MAGNETIC STEPPING MOTOR- Filed July 11, 1927 Patented May 6, 1930 UN ITED STATES EMILE QUARTIER,. F NEUCHATEL, SWITZERLAND MAGNETIC STEPPING MOTOR Application filed July 11, 1927, Serial No. 204,974, and" in Switzerland September 23; 1926.

This invention refers to an automatic control device for an electromagnetic device, for instance for an electromagnet for rewinding a clock movement.

ii It comprises a movable contact element mounted in the circuit of the electromagnetic device, independent of the movable portion of this latter and designed to come into contact with this movable portion so as to conm trol the circuit of the electromagnetic device, and this element is under the action of a spring and so arranged that its first contact with the movable element of the electromagnetic device takes place in a different position to that in which the breakage is produced, so as to ensure satisfactory operation of the controlling device, in the event of prolonged use.

I The annexed drawing shows, by way of 2d example, a constructional embodiment of the control device, applied to an electromagnet, producing the rewinding of a clock movement.

Figs. 1 and 2 are diagrammatic views showing the device in two difierent positions.

The electromagnet is constituted by a shell or skeleton of U shape, on the two arms of which are mounted the bobbins l3 and 13 for the windings. Opposite the extremities 11 and 12 of the skeleton frame 10 is pivoted at 15 a bent armature 14 which is under the action of a spring 16 operating a pawl 17 pivoted at 17' at its extremity. This pawl 17 is in engagement with a ratchet wheel 18 in fixed connection with the winding spindle 19 of a clock movement not -shown on the drawing. 7

At the extremity of the portion of the armature 14 located opposite the electromagnet, the said armature carries a contact piece 20 adapted to come into contact with a contact piece 21 mounted on a pivot piece 22 but insulated therefrom, which piece 22 turns upon an axis 23 and is under the action of a spring 24.

The contact piece 20 of the armature 14 is located between one extremity 26 of the contact piece 21 and a projection 27 on the pivotally mounted piece 22.

The spring 24 is connected on the one hand to a projection on the contact piece 21 and on the other hand to a fixed terminal 25 connected to a winding of the bobbin 13. It is so arrangedas to act upon the contact piece 21 and the pivoted piece 22 in such a way that either the extremity 26 of the contact piece 21 or the projection 27 onthe piece 22 is in contact with the contact piece 20 of the armature 14.

The operationof this device is as follows:

In the position shown at Fig. 1 the contact piece 20 of the armature 14 is in contact with the extremity 26 of the contact piece 21. The electric circuit ofthe electromagnet is thus closed, passing. from the negative pole of a source of current, for instance of a battery,

through the winding of the bobbin 13, the winding of the bobbin 13 the terminala25, the spring 24, the contact piece 21, the contact piece 20, the armature 14 and then returning tothe positive-pole of the source of current. By reason. of the closing of the electric circuit just explained the armature 14 is moved through the attraction of the electromagnet into the'position shown in .dot and dash lines at Fig. 1.

Owing to its displacement, the armature 14 causes the pivoted piece 22 to turnaround its axis '23 by means of the contacting piece 20. The result is that the extremity 26 of Y the piece 21 rubs against the contact piece 20. The spring 24 is stretched until the moment when it is exactly in the pivotal axis 23 of the piece 22. Assoon as it passes this point it extends and causes a sudden break as of the contact established between the piece 20 and the extremity 26 of the piece 21. The parts are then inthe position shown at Fig.

2 in which the circuit of the electromagnet is open as regards the contact 21. The projec- Jo tion27 of the pivot piece 22 is then in engagement with the contact piece 20..

At each displacement of the armature 14 the pawl 17 slipsteeth on the ratchet 18 as shown in dot and dash lines at Fig. 1 and the spring 16 stretched by the attractionof the electromagnet 'causesthe pawl 17 to come back to its position represented in full lines at Fig. 1,.little by little, .in conformity with the working of theclockmovement.

Upon the return movement of the armature 14 under the action of the spring 16, the spring 24: is again stretched by reason of the displacement of the piece 22 by the projection 27 which is in contact with the piece 20, until the moment when it has passed the pivotal axis 23. It then extends suddenly and again closes the circuit of the electromagnet to the contact 20, 26. The device thus works automatically as long as it receives current from an electric source.

By reason of the displacement of the contact pieces 20 and 21, the extremity 26 of this latter rubs upon the first mentioned, which causes a cleaning OK, in particular of the oxides coming from the sparking, and in addition to this the first contact between the two pieces takes place in another position to that in which the breakage of the contact takes place, which ensures a satisfactory working of the controlling device in the course of prolonged use.

The contact piece 21 may be arranged in another manner to that shown on the drawing. In place of being fixed on the pivoted piece 22 it might for instance be mounted independently of this latter and be simply controlled thereby.

The electromagnetic device might be a solenoid in place of an ordinary electromagnet and it might be used for other purposes than the winding of a clock movement.

What I claim is:

1. In an automatic controlling device for an electro-magnetic winder, an armature for the electromagnet, a circuit closer, said armature and circuit closer being in circuit with said electro-magnet, said circuit closer including a plate oscillatably mounted, having abutments between which a portion of the armature acts for initiating the oscillatory movements of said plate in either direction, one only of said projections being a circuit terminal, the path of oscillation of said terminal being difierent from the path of movement of said armature, whereby the point of contact between said terminal and armature is shifted during the interval in which these parts are in contact, and a spring activated by said armature, through said circuit closer for suddenly moving the latter to break the circuit at the end of said interval of contact.

2. A device for electro-magnetically winding a clock movement comprising an electromagnet with armature and circuit closer actuated thereby, said armature and circuit closer being in circuit with said electro-magnet, a pawl on said armature, in driving engagement with a winding wheel of said clock movement, a drive spring imparting the driving urge to said pawl, and biasing the armature away from said magnet, said spring being arranged to hold said pawl constantly in engagement with said winding wheel, said circuit closer including a plate oscillatably movements of said circuit closer, arranged to contlnue the movements of sald circuit closer,

uius producing sudden respective interruption of the circuit and reclosing of the same according to the direction in which the armature moves.

In testimony whereof I affix my signature.

EMILE QUARTIER.

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