US2442170A - Governor - Google Patents

Description

R. M. HEINTZ May 25, 1948.

GOVERNOR Original Filed Dec. 15, 1943 INVENTOR. ,BY RALPH M. HEINTZ ATTORAEY Patented May 25, 1948 I v 2.44am

covsanoa Ralph M. lieintz, Cleveland, Ohio,

mesne assignments, to Jack dz aulgncr, by Heintl, Inc.,

Cleveland, Ohio, a corporation of Ohio Original application December 15, 1943, Serial No.

514.388. Divided and this 17, 1945, Serial No. 573,195

1 Claim. (Cl. 20080) This invention relates to a governor for electric motors and the like, the present application being a division oi my application Serial No. 514,388, filed December 15, 1943, and entitled "Automatic pilot turn rate control.-"

The general object oi the invention is to provide a novel governor control for motor driven mechanisms wherein the governor is adjustable in operation by means of an external electrical control circuit.

A more specific object is to provide a novel governor switch having electromagnetic biasing means remotely adjustable by an external circuit for response to diflerentspeeds.

These and other objects will become apparent to those skilled in the art as the specification proceeds in connection with the accompanying drawings, in which: a

Figure 1 is an elevational view of an electric motor provided with a governor according to the present invention.

Figure 2 is a longitudinal sectional view through the governor taken on the line 2-2 of Figure l and including a schematic wiring diagram of the control and power circuits for the governor and motor, and

Figure 3 is a partial view taken as Figure 2, but showing the angular position of the contact arm in greatly exaggerated relation to illustrate the principles of the invention.

The invention is illustrated in association with an electric motor 4 which'is ofgeneral application wherever a variable speed motor drive is desirable and is particularly adapted for the use specified in the parent application. The governor device is indicated generally by the numeral I and is mounted on the motor shaft I.

As shown in Figure 2, the governor parts are carried by an insulating base i in the form 01 a circular plate adapted to be secured to the end of shaft 8. One side of the base i carries a pair of conductor rings I and adapted for engagement by a pair oi brushes It and I I, and the other side of the base carries a metallic cover member I! adapted for engagement by a single brush It. The cover member I! is made terial and is cup-shaped to accommodate a solenoid ll having an iron core in One end of the 'solenoid circuit is grounded ongthe cover I! and the other end makes electrical connection with the outer conductor ring 8. Secured to the base 1 by .a rivet l8 making electricaliconnection with the inner conductor ring 8 is va" -.,spring contact arm ll carrying an armature a of magnetic material bridging the core II and the rim i8 application January of the cover II. The armature I 8 thereby completes the magnetic circuit through parts I! and I5, except for small air gaps suflicient to prevent the armature from actually contacting the core or cover. The arm ll carries at its extremity a contact adapted to engage an adjustable contact 2| mounted on and grounded to the cover member II, the normal closed circuit position of the arm l'l being determined by the adjustment of contact 2!. A mass of metal 23 is provided opposite the contact II to balance the device" in rotation.

As shown in exaggerated representation in Figure 3, the arm I! in its normal closed circuit position makes a small angle A with respect to a perpendicular 12 to the shaft 6. Upon rotation of the shaft, centrifugal force tends to swing the arm toward this perpendicular, or from the full line position to the broken line position, but is restrained from such movement by the magnetic attraction or the armature it toward core is and rim it when the solenoid I4 is energized. Thus it will be seen that the magnitude of the restraining force acting on arm I! will be directly proportional to the current in solenoid l4. this being the only variable involved since the conof magnetic matact 2! is not intended to be adjusted after the device is assembled.

It is accordingly a primary advantage of the present governor that the speed at which the contacts 20, 2| separate may be adjusted or preselected at a remote station by simply controlling the current in a control circuit through brushes Ill and IS, the brushes H and i3 forming a part of a power circuit to the motor 4. Inasmuch as the magnetic attractive force on armature i8 rapidly diminishes upon the slightest movement of the arm ii in a circuit opening direction, the breaking of the circuit is rapid and decisive, without possibility oi chattering of the contacts. Also, a desirable speed differential oi operation is provided because with a given solenoid strength the magnetic holding force on the armature when the switch 20, ii is closed is greater than the closing force when the switch is open, providing 'in-herently stable and non-hunting governing action. It may be mentioned that the angularity of the arm I! with respect to the perpendicular is also exaggerated in Figure 2, the angle A being in reality quite small.

In operation, the switch arm I 1 controls a power circuit through the armature 30 or the motor l, the armature Ill being connected with a battery Ii through one blade of a three pole double throw reversing switch 32. The reversing 3 switch 32 operates to reverse the battery connections to the iield ll of the motor I.

The control circuit for the governor solenoid it may be traced from the outer conductor ring a to a current measuring instrument II, thence throuzh a rheostat control II to the battery ii. The other side or the solenoid circuit connects with the battery through a switch I! which in the parent application constituted a station selector" switch. For the purpose of ex I plaining the operation of the governor it may, 7 be assumed that there is only one control station, asshown in Figure 2, the switch I! operating merely as an oil and on switch for the system.

An important advantage of the present sovernor is that the motor speed may be carefully set prior to operation of the motor since the control circuit through solenoid ll, instrument II, and rheostat I. is independent of the motor power circuit through switch 32. Once set, the

speed adjustment need not be changed unless the battery voltage changes or until a motor speed is desired. That is to say that successive motor operations at the same speed may ordinarily be had without altering this adjustment, the closing 01' switch 32 effecting motor operation immediately at the desired speed.

The face of the instrument ll may be calibrated in units of rotation speed or in other units indicative of the eflects produced by motor operation, as disclosed in the parent application.

Various other changes and modifications may proximately in a plane normal to said shalt, a

cup-shaped cover member of maanetic material axially disposed on said base, a solenoid carried (within said cover member and arranged to bias said arm slightly out or said plane against the influence oi centrifugal force, a contact carried by and electrically connected with said cover member and serving as a stop for said arm, a

pair of conductor rings carried by said base, electrical connections from said solenoid to said cover member and one of said conductor rings, and an electrical connection from said arm to said other conductor ring. i

. RALPH M. HEINTZ.

I anrnaanons crran The following references are of record in the flle of this patent:

be made within the spirit and terms or the appended claim. For instance a zero center instrument may be used in place 01' instrument as to 1,632,565

UNITED STATES PATENTS Name Date Creveling Mar. 27, 1900 Schmidt June 14, 1927 Number

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