US2475269A - Antihunting means for remotecontrol systems - Google Patents

Description

-July 5, 1949. M. N. YARDENY 2,475,269

ANTIHUNTING MEANS FOR REMOTE-CONTROL SYSTEMS Filed Feb. 27, 1943 JNVENToR.

MICHEL N. MRDENY 50' l 1110 M55 OY M W Patented July 5, 1949 UNITED STATES PATENT OFFICE ANTIHUNTING MEANS FOR REMOTE- CONTROL SYSTEMS Michel' N. Yard'eny, New York, N. Y.

Application February'27, 1943, Serial No. 477,469

4 Claims. l

My invention relates tol remote control systems and has particular reference tok systems employing electricmotors with control devices for bring ing two or morev controlled members into exact require'dposit-icn's.

My invention has further' referencey 'to-control systemsappara-tus in whiclri al reversible electric motor isemployed for operatingA a use'- ful load, said motor having reversing windings connected directly ror through a suitable relay or relays with twor control elements for producing relative movements between the lcont-rol elements, one-.of the control elements comprising4 a1 pairl off conducting members separated by a.. gap andithe otheracontactor in;1 aL slidingl engagement withL the. conducting members, the motor being so connected. in al circuit with? the control elements that it is stopped when the contacterengagesthefgap.

One off thee main` objects of' my: invention is to provide an apparatusl orsystem' whereby: a useful.4 load can be. moved. al predetermined number of complete' revolutionsand then `adesired fram tion of onev revolution for one cycle: of move ment ofithecontrol elements. Anapparatus of this type may 4be described as a multi-revolution device.

Anothery object` of :'my: inventionI isV to provide means for placingthe conducting members accurately ini any desired. position,l each pair of conducting members being` capable of being adjusted withinalmost. 360.o or almost a complete circle.

Another object of my inventionisvto reduce sparking at the contacts betweenthe conducting members andthe contacts When-rotation of the motory is. reversed y or when thecmotor is stopped. Ii accomplish thisfby using special relays: consuming a. verysmall amountof electric power; alsoby using condensersv and resistors in the current interrupting circuits.

.Anotherf'objectiotmy invention isto provide an apparatusvof. thefff'oregoing general typel with further improvements. for. its satisfactory operation.v Onev of such. important improvements consists insth'eprovision 'for suppressing and en-V tirelyK eliminatingeosci'llations.or hunting of fthe motor: when the. conta'ctor'. engag'esthegap .and the motonmust be' stopped.` If have yfound'by actual experience that 4such-afresultcan be ob'- tained when .using a "combinationA of certain *elec-A trical and mechanical .features -as .disclosed -more fully in the' appended specification. Certain of these features can' be. used, however, not only with the remote control systems but also with other systems employing reversing motors.

I also provide means to combine electric with manualcontro'ls, to be used selectively, the oscillation-suppressing features being automatically eliminated when the manual control is used.

My invention is more fully described in the accompanying specication and drawings in which Fig. 1 is a diagrammatic view of my remote control system in one of its modifications;

Fig. 2 is a similar diagrammatic View of the system, showing electrical' connections;

Fig. 3- is a detail view of a driving gear and friction clutch, taken on theiine 3 3 of Fig. 2;

Fig. 4 is a diagrammatic View of a system with a shunt motor; and

Fig. 5 is a detailed view of an arrangement of the control elements.

My remote control system is represented in one of its modiiic'ations in Figs. 1, 2 and 3, Fig. 2 showing the complete circuit diagram. It consists of a reversible electric motor With reversing windings 2, '3, Fig. 2. The windings are connectedatl the common tap 4 by'a lead and an interruptor 5U, 5|', 52 or leads 93, 94 and a rotary ' switch 53, 55, 56, 5l as` will be explained more fully l'ierein'a'fter;y 5 with one terminal of asource of cur-rent 6, the other terminal being connected by a lead-l with a `contacter 8. The latter can be 'placed in-any desired position by a manually or otherwisecont'rolled device 9, indicated dia'- grammatically vin` Fig. 1. The contactor has a pointer= lindicatingits position on a scale The contactor also hasla contact'point I2 adapted to'bridgelthe gaply I3 between members I4, I5., made of a convducting'-`v material and which may bein theformofy segments so that they Will be for convenience'called segments. The segments areuc'onnec'ted'by flexible leads I6, H with the endsi'of the coilsil, |9of`a suitable'r'elay acting on'switches 20, 2| for causing the switches toengage contact pointsl 22,' 23, connected through a'lead 1241Wi1th the' second terminal of the'sourc'e 'of'c'urrent' Normally' the switches 20, 2| engage contact points 22', 23 ofthe coils 2, 3.- It will be seen-'that current will flow through vvone of l4therelay'fcoils I8 or'- |9 when the contact' member engages by its pointedy l2 one of Ithe'segments I4" or l5. The' corresponding switch 20 or12f| will be then attracted vby the en ergized relay coil, causingV the current also to flow' through' one of the motoreldwindings 21er 3: The motoriwill rotatein a 'corresponding."r direction, turning the segments through worm 25 and 21 and worm gears 26, 24' or through some other gear arrangement. The pinion 25 may be connected by a shaft 29 with a useful load 38 which may be a tuning condenser, etc. The rotation will continue until the gap I3 is bridged by the contact member I2 whereby -both relay coils will be energized with a result that both switches 2D, 2l will be deflected, disconnecting the motor windings 2, 3. The motor will be therefore, deenergized and stopped. The gap portion I3 is narrower than main gap I3 so as slightly to enlarge the extent of the contact surfaces I4, I5 and thus somewhat to increase the range of the possible positions of the disk, thereby also increasing the range of the possible load positions.

The segments are suitably mounted on a comn mon shaft 29' with the gear 24', concentric with the shaft 28 of the contactor 8.

With the double gear reduction as shown, the shaft 29 of the load 38 will make several revolu tions for one revolution of the indicator I6. It will be therefore possible to turn the shaft 29 through several revolutions and to stop the same exactly in a desired position as indicated by the pointer I0 on the scale I l.

Since it is preferable to use a small high speed motor with my system, it is also necessary to take steps to prevent overrunning of the indicated position by the rotating members by inertia, which overrunning may result in oscillations or hunting of the motor. One of such devices for suppressing motor oscillations is shown. in Figs. 1 and 2 and consists of a flywheel 3l, freely rotatng on the motor shaft 28 but connected with the shaft by a friction clutch 32, pressed against the side of the Iiywheel by a spring 33. Pressure of the spring may be regulated by a nut 34. The effect of the iiywheel is such that it will cause an increased drag on the shaft when the motor a rotation is reversed, tending to retard the rotation after reversals and thereby stopping the hunting or oscillations.

An additional hunting-suppressing means consists of a frictional clutch between the gear 26 and shaft 29 as shown in Fig. 3. The gear is loosely mounted on the shaft 29 but prevented from rotation by a pin 35 engaging a slot 36. The latter, however, is sufficiently wide to allow for a certain amount of free motion of the gear 0n the shaft. The gear is further engaged to the shaft by a friction clutch plate 31, slidably keyed to the shaft 29 and urged by a spring 38 against the face of the gear. Spring tension can be adjusted by a nut 39, Fig. 3.

Tension of the clutch is so adjusted in relation to the resilient friction of the contact member I2 in the gap that the clutch will slide when the motor is deenergized by the gap being bridged by the Contact member I2 and the motor continues to rotate by inertia only. The contact member will therefore be locked in the gap without any back and forth oscillations. Clutch friction will dissipate the inertia rotational energy of the motor, eiectively stopping the latter while it is still deenergized.

Gears 40, 4I are provided for manual operation of the device as shown in Fig. 1. The gear 4I is mounted on a shaft 42, sliding in bearings 43 and being urged upward by a spring 44. The shaft can be rotated by a thumb head or handle 45 after it is depressed for bringing the gear 4I into engagement with gear 40. At the same time a cam 46 mounted on the shaft 42 engages one end of a lever 41 whose other end is pivoted at 48, the middle portion of the lever engaging a cup-shaped member 85, Fig. 3, with teeth 86, engaging corresponding holes 81 in the gear 26. A spring 88 normally keeps the cup-shaped or toothed member away from the gear. With this arrangement the lost motion between the gear and the shaft 29 is eliminated when the manual control is used, the toothed member 85 being slidably keyed on the hub of the clutch member 31.

As an added arrangement for eliminating lost motion between the gear 26 and worm 21, the gear may be made of two parallel discs 26', 26, sliding in relation to each other but connected together by helical springs 49 fitted in slots 43'. The springs are given initial tension when the gear is brought into mesh with the worm, causing the two halves of the gear to press at the worm teeth from the opposite directions.

I have also found that motor hunting is also largely suppressed when two successive worm drives are employed as shown in Fig. 2, because of the increased friction of such drives.

As an additional means to suppress oscillations I use a vibrating interrupter 5U, Fig. 2, connected in series with the motor in the lead 5. Current passes through the interrupter coil, vibrating armature or arm 5i, and contact point 52 to which the armature is urged by a spring 89. A resistor 50 is connected parallel to point 52 to suppress sparking. The interrupter is normally short circuited by Wires 93, 94, extending to contact points 53, 51. The motor shaft consists of two portions, 28 and 54, connected together by a hook 55 on the shaft 28 engaging a lug 56 on the shaft 54. The points 53, 51 are in electric Contact with each other as long as the shaft 28 drives the shaft 54 in one or the other direction, but as soon as direction of rotation changes, i. e., when the contactor I2 passes over the gap to the next segment I4 or I5, the hook 55 leaves the lug 56 and makes one revolution before engaging the lug again from the other side. In the meantime the leads 93, 94 are disconnected so that the Vibrator becomes operative, effectively stopping the motor when the contactor reaches the gap.

The effect of the vibrator is such that the motor is slowed down when the contactor engages the segments at the gap, thereby losing its tendency to oscillate, rapidly reversing its rotation.

A lamp 60 or other suitable signal device can be placed in the motor circuit to indicate operation of the device.

A fri-ctional clutch 58 (see Fig. 1) may be also provided between the shaft 54 and the worm so adjusted that the motor can drive the load through the clutch, but when manual means is used for turning the worm 21, the clutch permits rotation of the worm without turning the motor shafts 28 and 54. Voltage for the relays may be reduced by the use of a potentiometer I43 or similar device such as transformer, etc.

To increase the accuracy of the control and as means to suppress motor oscillations or hunting of the motor, provisions may be provided to increase friction between the contactor and the conducting segments at the gap. Such arrangements are shown in Fig. 5 and consist in raising the edges |38 of the segments I4 and I5. Such arrangements are of particular advantage when thin segments are used to avoid deflection of the segments by the pressure of the contactor. The edges are raised at the main gap I3 only, the

other gap I3' being narrow, this gap never being bridged by the point I2 of the contactor 8.

To increase the accuracy of the system and as an additional means to suppress motor oscillations, provision is made to increase friction between the conductor and the conducting segments at the gap. According to Fig. 5, the edges of segments I4 and I5 forming gap I3 therebetween are raised at |38. The tips of the segments are bent downwardly to rest upon disk 12, thereby avoiding deflection of the engaged segments by the contact pressure.

As shown in Fig. 4 coil 5U is connected by means of leads 93, 94 to contact brushes 53, 51 engaging contact rings 91, 98 on the hubs of lug 56 and of hook 55. f

A direct current motor I 48 can be used with my system as shown in Fig. 4, current passing through the armature of the motor through leads I4I, |42. A spark suppressing resistor |41 is lncluded in the armature circuit. When one of ythe shunt iield windings 2 or 3 is energized, the

resistor is short circuited by a magnet |44, connecting the switch arm |45 directly with a lead |46. The transmission between motor |48 and segments I 4, I5 is shown only diagrammatically and is of the same type as illustrated in Fig. 2.

I claim as my invention:

l. A control apparatus comprising relatively movable control elements; reversible drive means adapted to operate a useful load; transmission means arranged to be operated by the drive means for producing relative movement between the control elements, said transmission means being arranged to cause the control elements to complete one cycle of movement for more than one cycle of movement of the drive means; means to control the drive means by the relative position of the control elements, and to render the drive means inoperative in response to the control elements occupying a predetermined relative position; and anti-hunting means comprising means for reducing the rate of movement of the drive means and means for rendering the reducing means operative for a fraction of one cycle of movement of the drive means in response to a reversal of the drive means.

2. A control apparatus comprising relatively movable control elements; a motor; reversible rotary drive means operated by the motor and arranged to operate a useful load; transmission means arranged to be operated by the drive means for producing relative movement between the control elements, said transmission means being arranged to cause the control elements to complete one cycle of movement for more than one cycle of movement of the drive means; means to control the direction of movement of the drive means by the relative position of the control elements and to render the motor inoperative in response to the control elements occupying a predetermined relative position; and anti-hunting means comprising means to reduce the rate of rotation of the motor by periodically interrupting its energy input and means to render the antihunting means operative for a fraction of one revolution of the drive means in response to the reversal of the direction of rotation of the drive means.

3. A control apparatus comprising relatively movable control elements; reversible drive means adapted to operate a useful load; transmission means arranged to be operated by the drive means for producing relative movement between the control elements, said transmission means being arranged to cause the control elements to complete one cycle of movement for more than one cycle of movement of the drive means; means to control the drive means by the relative position of the control elements, and to render the drive means inoperative in response to the control element occupying a predetermined relative position; and anti-hunting means comprising means for reducing the rate of movement of the drive means and means for rendering the reducing means operative for a fraction of one cycle of movement of the drive means.

4. A control apparatus comprising relatively movable electric control elements; a reversible motor adapted to operate a useful load; transmission means arranged to be operated by the motor for producing relative movement between the control elements, circuit means to control the motor by the relative position of the control elements, and to render the motor inoperative for the purposes aforesaid in response to the control elements occupying a predetermined relative position, the said transmission having a driving portion and a driven portion, dogs secured to the said portions and arranged with the driving dog in abutting driving relation with the driven dog, electric means for reducing the speed of the said motor included in a circuit with the motor, and a by-pass circuit including the said dogs and speed reducing means, the said driving abutment between the dogs completing the said by-pass circuit to render the speed reducing means normally ineffective and breaking the said by-pass circuit during the time the driving dog is disengaged from the driven dog upon reversal of motor rotation.

MICHEL N. YARDENY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 645,766 Sundh Mar. 20, 1900 1,271,362 Rainey July 2, 1918 2,094,777 Ellinger Oct. 5, 1937 2,204,065 Beizer et a1 June 11, 1940 2,331,354 Stout Oct. 12, 1943 2,342,717 Yardeny a Feb. 29, 1944

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