Electric-motor controlling device
US 513213 A
Description (OCR text may contain errors)
(o Model.) 2 Sheets-Sheet I. J. E. STANTON.
ELECTRIC MOTOR CCNTECLLINC DEVICE. No. 513,213. Patented Jan. 23, 1894.
Wl'rNEssEs Fig.; INJENTDR iNo Model.
2 Sheets-Sheet 2. J. E. STANTON. ELECTRIC MOTOR GONTROLLING DEVICE. No. 513,213. Patented Jan. 23, 1894.
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rigf. WITEESES IM/ENTI: aka/@ @WM UNITED STATES PATENT OFFICE.
.TERE E. STANTON, OF BOSTON, MASSACHUSETTS.
ELECTRIC-MOTOR CONTROLLING DEVICE.
Application filed J une 19, 1893.
To all whom, t may concern:
Be it known that I, .TERE E. STANTON, of Boston, in the county of Suffolk and State of Massachusetts, have invented new and useful Improvements in Electric-Motor Controlling Devices, of which the following, taken in connection with the accompanying drawings, is a specification.
My invention consists of an improved controlling device for electric motors whereby the motor may be instantly started, stopped reversed or varied in speed in either direction by the foot of the operator.
There are various machines to which electric motors are applicable for furnishing the motive power in which it is desirable to have the speed either direct or reverse not only under immediate control, but capable of being controlled in such a manner that the operator has both hands free at all times for the particular manipulation of the machine; such for instance is a dental engine which it is often desirable to vary greatly in speed and sometimes to quickly reverse without using either hand for the purpose.
It is with special reference to dental and surgical engines that my improved motor controlling device has been contrived, though it is equally applicable to a great variety of uses wherein the electric motor supplies the power.
The device consists of a pivoted pedal capable of being moved to the right or left by a turn of the foot. Connected with the pedal and movable therewith is an arm which is adapted to traverse a series of contact posts, throwing into circuit varying sections of resistance coil, on either side of the central or neutral point of the arm. This arm also operates a peculiarly contrived switch, the construction being such that when the pedal is in its central position the circuit is open; and when moved to one side, the arm, working in connection with the switch, brings into circuit through the motor, coils of varying resistance, thereby varying the speed at will'.
Referring to the accompanying drawings Figure 1 is a top plan view of a controlling device embodying my invention. Fig. 2. is a plan view of the interior mechanism, the top Serial No. 478,063. (No model.)
of the inclosing case being removed. Fig. 3. is a transverse sectional view through the center of the apparatus and Fig. 4. is a plan view in the nature of a diagram showing the method of connection between the battery, the motor and the various working parts of the controller.
A is the base board of the controller case and A is the top which is adapted to be screwed or otherwise attached to the sides of the case.
B is the operating pedal secured to the pivotal arbor b3 which turns easily within the top A.
C is an arm within the case connected with the pedal in such a manner as to be movable conjointly therewith. As herein shown the inner end c of the arm C has bearings between the bracket H and the plate H secured to the bottom of the case, and the downwardly project-ing arbor b3 interlocks with the part c in such a manner that both the pedal and the arm are movable together about the same axis which is preferably in the center of the heel of the operators foot as it rests upon the pedal. The pedal B at a point beneath the ball of the foot preferably has a bearing upon the arc shaped piece B2 as the pedal is moved to the right or left about its axis by a turn of the foot.
The arm C is virtually a bell crank lever the shorter arm C2 being pivotally connected through the link L with the sliding switch consisting of the slotted piece L of non-conducting material (guided to move back and forth over screws set in the base) and of the spring contact pieces L2 L3 Secured to the sides of the movable non-conducting piece L.
F F F4 are plates along which the contact piece L2 is adapted to slide as the switch moves, while F2 F3 and F5 are corresponding plates for the contact piece L2, the parts be ing so arranged that the spring pieces L2 and L3 are always in contact with the plates F4 and F5 respectively whatever the position of` the arm C; if the arm C is moved to the right said plates FAl and F5 are connected through the contact pieces with the plates F and F3 respectively. If the arm C is moved to the right.
the left, the plates F4 and F-5 are connected through the 'contact pieces with the plates F and F2 respectively. The insulation f separates the plates F and F' while the insulation f' separates the plates F2 and F2.
Conducting cross strips G and G serve to connect in pairs the plates F F2 and F F2, said conducting strips being carefully insulated from each other.
When the arm C is in its central position the forward end C' thereof rests upon the neutral plate d. When moved to the right the part C' of the arm traverses a series of contact posts cl' cl2-d' at various stages along a resistance coil D. de ri-d are corresponding series of contact pieces to the left of the central or neutral point d, connected at various points with the resistance coil D'.
The coils D D' are preferably arranged on the under side of the non-conducting plate E between it and the bottom Aof theinclosing case.
B' is an index on the front of the pedal B, whichin connection with the plates b b' and b2 indicateto the operator when the armO 1s on the neutral point d or in the contact posts da or d'.
The generator or source of electrical supply is in the present case a storage battery, represented by Rin the diagram in Fig. 4, while M is thetield and N the brushes of the motor to be controlled.
The wires o oo11 connect the various parts of themechanism ot' the controller with themotor and' battery through the binding posts along the s i'de of the case, the particular arrangement of the connecting wires being obvious from the operation of the mechanism which will now be described. v Suppose the motor to be driven with a direct or right handed motion by turning the pedal to When the pedal is on the central or neutral 'point the motor is stopped since in that position the circuit is broken. By turn-v ing the pedal to the left the currentis turned in the opposite direction through the motor which is thus reversed. The speed either director reverse is vat its minimum when the partC' of the arm C is on the posts d' or d8 and its maximum when the part C' is on the posts d7 or di".
Suppose the pedal to be moved tothe right with the part C on the contact post d'. In this position the sliding switch by means of the spring contacts L2 L3 connect the plates F' and F 4 on one side and the plates F3 and F5 on the other. The track of the current from the storage battery is then traced as follows:from the battery along wire o, `through binding post R' to bracket H,.arm C C' to'contact post d' through coil D to d7, through wires o2 and oB to plate F4, thence through contact spring L2 to plate F', and from there through strip G to plate F2, then through wire o4 to binding post N', to wire o5,
to brushes N on the motor, to wire o6, binding post N2, wire o2 to plate F, through strip G' to plate F2, through contact piece L3 to plate F5, through wire os to binding post M', wire 09 through eld M of motor, wire 010 binding post M2 and wire 011 back to battery.
If the pedal be turned to the extreme right with the parat C' on the contact post (i7 the resistance coil D will be cut out of the above circuit and the speed will of course be greatest, the speed being proportional to the amount of the resistance coil put in circuit,
`or, in other Words, with the angular position of the pedal.
with the pedal B to the left of the neutral' point, say with the part C' of the arm C on the contact post d2,t he switch L is moved forward and the track of the current is thus tracedz--from-battery R along wire o to binding post R', wire Q ',bracket H, arm C C', contactpost d2, coil'D', wire o2, plate-F4, contactA pieceL2, plate F, wire o2, binding-post N2,
wire o, motor-brushes N, wire 0,"bindingpost N', wire o4, plate F2 contact piece L2, plate F5, wire o8, binding postV M', wire 09,-' motor field M, wire 010, bindingjpost M2, Wirefou'back to battery. u
P. representsthe pulley of the motor from which through the beltsP' power is transmitted to the dental engine or other machine to be driven. V
The inclosing case withthe controller therein rests preferably upon the iioorv near-the machine to be operated, in such a; position that the operator by a very slight movement of the foot upon the pedal may at will instantly vary the speed and directionof movement in accordance with the particular work to be done and in avery simple manner, having both hands free for the manipulation of the machine. c
I claim-a 1. In combination, au electric circuitthrough a motor and generator, a pedal operatedpivoted arm forming a terminal of the circuit, a resistance coil on each side of the arm, each coil being provided with contact postsat various stages ot' said coil adapted to be traversed by said arm, a sliding switch oper'- ated by said arm, and suitable contacts for said switch whereby a greater or less portionl of either coil may be t-hrownintocircuit and the current sent through the motor in one direction or the other and in varying intensity according to the positions'of the armV and switch substantially as described.
2. In combination, an electric circuit'through a motor and generator, the` laterally movable pivoted pedal B, the bell crank lever C C2 movable with, and about the same axis as the vpe`dal,resistance coils D D' having contact posts adapted to be traversed by the long arm of said lever, the sliding switch L L2Ls movable bysaid lever, contact plates F, F',
F2 F3, F4 F5, and suitably arranged conduc- IOO part of a circuit through a motor and generator substantially as described.
In testimony whereof I have signed my name to this specification, in the presence of 15 two subscribingr witnesses, on this 10th day of February, A. D. 1893.
J ERE E. STANTON.
ALBERT E. LEAOH, M. T. LEAOH.