US1845375A - Electric controller - Google Patents

Description

Feb. 16, 1932. R. EJWEIMER ELECTRIC CONTROLLER Filed March 2o, 1930 .gum

- IIIIIIIIIIIIIIIII l n lvl I I i 1 l l l INVENTOR Patented Feb. 16, 1932 UNITED STATES ,PATENT OFFICE ROBERT E. WEIMER, OF COLLIERS, WEST VIRGINIA, ASSIGNOR TO WEIMER-WARREN COMPANY, A CORPORATION F WEST VIRGINIA ELECTRIC CONTROLLER Application led March 20, 1930. Serial No. 437,517.

My invention relates to electric controllers and systems for electric motors.

It is the object of this invention tol provide an improved means for automatically cutting out resistance from a motor circuit after )o Fig. 1 is a vertical section of my improved controller, parts appearing in side elevation. Fig. 2 is a diagrammatic view of a motor system in which my controller is incorporated.

On the drawings,1designatesa base or plate of insulating material such as slate which supports the switch 2 connected thereto by the pivot pin 3. The switch has the upstanding member 4 provided at its upper end with the contact 5 and intermediately of its ends with the armature 6. 7 is a fixed contact cooperating with the contact 5 and connected to the base 1 by the terminal bolt 8 which extends entirely through the base and is secured thereto by the nut 9 at the back of the base. The nut 10 works on the bolt 8 and clamps the wire 11 between itself and the nut 9.

The electromagnet 12 is secured to the back of the base and has its magnetic core extending through to the front of the base where it terminates in the magnetizable head 13 arranged opposite to the armature 6 which is spaced from the head when the controller is idle. One terminal of the winding 14 of the electromagnet is connected to the terminal bolt 15 which is secured to the base while the other terminal of the winding is secured to the terminal bolt 15 at the back of the base, the wire or jumper 16 connecting the terminal bolt 15 at the front of the base to the switch member 4.

17 is a vertical electromagnet having the winding 18 which actuates the core armature 19 having its upper end provided with the insulated head 20. This head is arranged beneath the lateral member 21 of the switch 2 so that when the armature 19 is forced up suiiciently far the head by engagement with the member 21 rocks the switch 2 until it assumes the position shown in dotted lines in Fig. 1 where the contacts 5 and 7 are engaged with each other and the armature 6 is engaged with the head 13. One terminal of the winding 18 is connected to the negative line terminal 22. The other terminal of the winding 18 is connected by the wire 23 to the bracket 24 attached to the base 1 and having its free end 25 provided with the adjustable screw Contact 26 arranged to engage the contact block 27 on the switch member 4 when the latter is in its open position as shown in full lines in Fig. 1.

28 is the positive supply line which is connected to the terminal bolt 15. 29 is the motor armature which is connected to the line 28 through the resistance 30. The shunt field winding 31 of the motor is connected across the positive supply line 28 and the negative supply line 32 through the winding 14, The connectionbetween the two windings is made by the wire 33.

rl`he lower end of the armature has the piston 35 working in the barrel 34 of a dash-pot, the barrel having a vent 36 opening into the dash-pot barrel below the piston when the latter has travelled upwardly such a distance as to cause the head 20 to approximately reach the switch member 21.

Current having been supplied to the lines 28 and 32 flows through the resistance 30 and the armature 29. Current also flows from the line 28 through the holding winding 14 and field winding 31. The rush of current through the armature starts the motor at a high speed which is reduced as the back E. M. F. builds up. In order to increase the motor speed the resistance 30 is cut out of the armature circuit in a manner now to be explained.

Current flows initially from the line 28 through the terminal bolt 15, the jumper 16, the switch member 4, the contact block 27, the contact 26, the bracket 24, the wire 23, the winding 18 and the terminal 22 to the negative line 32. The flux generated by current in the winding 18 lifts the armature 19 slowly under the control of the dash-pot. After a predetermined interval of timethe piston 35 passes the vent 36 whereupon the dash-pot control of the armature ceases. The

armature is then very quickly pulled upwardly and engaging the member 21 forces the switch 2 from the position shown in Jfull lines to the position shown in dotted lines in Fig. l. The current just described is opened at the contacts 26 and 27 and the contacts 5 and 7 are practically simultaneouslyV closed, the switch 2 being held in its closed position by the magnetic attraction between the armature 6 and the magnetized head 13. The opening of the contacts 26 and 27 and the closing of the contacts 5 and 7 establishes a new circuit, current flowing therein from the positive line 28 through the'terminal bolt l5, the jumper 16, the switch member 4, the contacts 5 and 7, the wire 11, and the armature-'29 to the negative line 32. The wire 11 joins the armature circuit at the point 37V which is between the armature 29 and the resistance 30. VThus, the armature current now short-circuits the resistance 30 causing thev motor to rotate at a higher speed.`

Upon the opening of the contacts 26 and 27 the magnet 17 becomes (le-energized and the armature 19 drops to itsinitial position ready for f another; acceleration operation when theV switch 2 drops open as it will when the line circuit is open and the holding winding 14 is thereby (le-energized.

I claim: Y 1. In an electric motor system, current supply lines, a motor armature, a lresistance iniv tially in series therewith, a shunt lield winding, an electromagnet, a switch member in its initial position'connecting the winding of the electromagnet across the lines and in anothervposition closing a shunt around the resistance, an armature operated by the electromagnet to move the switch member to its second position, and a time-limit means for causing the armature to vmove the switch member to its second position after aprede termined interval.

2. In an electric motor system, current supl ply lines, amotor armature, a resist-ance initially in series therewith, a shunt Held winding, an electromagnet,l a switch member in its initial position connectingithe winding. oit' the electromagnetacross the lines and in a circuit in parallel with the resistance and in another position closing a shunt around the resistance, an armature operated by the electromagnet to move the switch member to its second position, a'time-limit meansfor causing the armature to move the switch member toits second position after a predetermined means for electro-magnetically holding the switch member in its second po- Y sition.

, 3. In anelectricmotor system, current supply llnes, a motor armature, a resistance ini` tially in series therewith, a shunt field wind- Y ing, an electromagnet, afswitch member in Aits initial position connecting the winding of the electromagnet across the lines and in

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