US2200728A - Control apparatus - Google Patents

Description

y 4, 1940. H. WALKER 2.200.728

CONTROL APPARATUS Filed April 18, 1938 2 Sheets-Sheet 1 INVENTOR. H o NAED NHL KER B 0 Arrozrmyg y 9 1940- H. WALKER 2.200.728

CONTROL APPARATUS Filed April 18, 1938 2 Sheets-Sheet 2 Con fro] Pbm'f Fig. j

INVENTOR. BY How/7,90 NHL/(7? ATTORNEYS Patented Mi, 14, 1940 UNITED, STATES oon'mor. APPARATUS Howard Waller, Chicago, 111., assignor to Bendix Radio Corporation, Chicago, 111;, a corporation I of Delaware Application April 1a, was, Serial No. 202,682'

5 Claims. (oi. 172-239) This invention relates to control apparatus and more particularly to motor powered apparatus which may be operated lrom a remote point. The improved apparatus may be used for actuating electrical switches or for effecting other kinds of control functions.

An object of the invention is to provide improved apparatus in which motor power is used to move the controlling memberto some selected position and in which safeguards are provided forprcvcntingmovement of the control 7 member beyond the selected position.

y In motor powered control devices, it is a difficult problem to stop the controlling member at exactly the desired position, as the momentum of the motor tends to carry the movement on after the motor is deenergizeo, and this extra movement destroys the sccuracy of control in the common control system. To overcome such periods and in which the control member re-' mains motionless during the intervening periods.

- With this construction it is possible to stop the motor during the intervening periods and thus eliminate any actuation oi the control member due to the momentum oi. the motor and drive mechanism. As a further safeguard against the mechanism being moved on into the next period by the motor momentum, I provide means for throwing a reverse torque on the motor in case the mechanism should he moved by the force of momentum beyond a. certain point in the intervening period.

I have found also that especially when the member may he driven as rapidly as may be desired, and may he stopped at pro-selected positions with the positive guarantee that there can be no further movement to destroy the accuracy of the setting.

A further object is to provide improved apparatus in which the control member is rotatable, the driving means being adapted to rotate this improved device with the casing front removed;

member intermittently inlone direction to different angular positions corresponding with different control functions. Other objects and advantages will be apparent as the specification proceeds. 5

Av preferred embodiment of the invention is illustrated in the accompanying drawings in which:

Figure l is a front elevational view of the Figure 2 is a plan view with the casing shown, in section, the section being taken as indicated at line 2-2 of Figure 1;

Figure 3 is a rear elevational view showing one side of the rotary switch; V

Figure 4 is a detail view of the switch shown in Figure 3, the View being taken as seen from line 4-4 of Figure 2; v

Figure 5 is a detail view of the cam member employed for controlling the motor energizing circuits; and I Figure 6 is a schematic view showing the wiring arrangement.

As illustrated, A designates a casing or frame; B, a motor for supplying the necessary power to actuate the mechanism; C, themovable control member by which the control functions are efiectecl; and D, the'drive' mechanism through which the power of the motor is made effective to drive the control member to diiierent posh so tions corresponding with the control functions desired.

The frame or casing, A may be of any suitable material, preferably metallic, and may he of any suitable form. As illustrated, casing A includes 35 a rear portion A1 having forwardly turned edges, and a front portion A: having rearwarcily turned edges, these portions being adapted to be fitted together to form an enclosure. The screws 86 which extend between portions A1 and A2 form means for securing these portions in place.

At one end of the frame enclosure A. is an opening ll through which electrical connections n'lay be made and which is convenient for inin Figure 1 of the drawings.

produce rotation in the opposite direction. However, any suitable type of motor which is equipped with a circuit for setting up a reversing torque may be used. .In the embodiment illustrated, the motor shaft I3 is provided with a worm gear i4 which makes engagement with the toothed gear I5 keyed to the driving shaft l6. Through this engagement rotation of the motor is caused to produce rotation of the driving shaft. It is obvious that other means for connecting the motor in mechanical drive relation with the driving shaft may be provided if so desired. I

. The control member C is illustrated in the form of a shaft having flattened sides and extending through the rear frame portion A1. Within frame A is a hollow cylindrical sleeve l1 into which the end of shaft C is secured. This sleeve is equipped with a fiange ll on the front side of which is secured the gear 20.

The gear 20 has its peripheral portion formed into the general shape illustrated more clearly At spaced intervals along its periphery are the recesses 2| extending radially inward and having curved walls. It will be noted also that the portions 22 between recesses 2| are also of curved contour so as to engage the surface of the cam 22 secured on shaft l6. Cam 22 has a circular periphery except for the flattened side 22, and operates through engagement with the tooth portions 23 to maintain gear 25 locked and motionless except when the side 22* is adjacent these portions.

Secured on the drive shaft 16 just rearward of cam 22 is the driving arm 24 carrying. the forwardly extending pin 25. Arm 24 is aligned with the surface 22 of cam 22 and is adapted to pass rearwardly of gear 20 as driving shaft i6 rotates, the pin25 entering one of the recesses 2| to move gear 20. It will be observed that when pin 25 is moved to actuate gear 25, the side 22'- of the cam will have moved adjacent a peripheral tooth portion 23 so as to unlock the gear and leave it free to rotate; but as soon as pin 25 moves from the recess engaged, the circular surface of cam 22 engages the next of tooth portions 23 to again lock the gear against rotation.

Mounted in any suitable way in the frame are the spring contact fingers 26' and 26 which normally maintain the contacts 26 closed, and also the spring fingers 21' and 21 which normally maintain the contacts 21 open. The spring fingers 26 and 21 have their end portions extending over the driving shaft l5 and the lowermost'of these, 26'', is provided with a nose 25.

which rides on the cam 40 secured on shaft I6.

The cam 40 is shown in detail in Figure 5 of the drawings. It has three arcuate peripheral surfaces each concentric with shaft l6 and of different radius. As shownin Figure 5, the cam surface is of smallest radius, the cam surface 40 of medium radius, and the cam surface 4|! of largest radius. When the nose 28 rides on the surface 40, contacts 21 are open and contacts 26 are closed; when nose 26 rides on surface 40', the contacts 25 are open as well as the contacts 21; and when nose 28 rides on the surface 45", the contacts 26 are held open and contacts 21 are closed. As clearly shown in Figure 5, the junction between each of these cam surfaces is rounded and smooth so that the nose 2! may pass easily from one cam surface to the other. Though as here illustrated each of the above described surfaces extend over substantially equal parts of the cam periphery, this may be varied as may be desired. It is essential only that there be three successive cam positions for producing the three conditions of the contacts 26 and 21 as above described.

. Mounted on the rear side of frame A and having its rotor engaging the control shaft C, is the switch shown more clearly in Figures 3, 4 and 6. On the rear side of this switch (Figure 3) the rotor is provided with three conductor segments 59 each of which has one. tooth. The contact 51 mounted on the stator is adapted to make contact with the arcuate or inner part of the segment while the contacts 52 and 53 and 54 are adapted to make contact only with the tooth of a segment.

On the other side of the switch (Figure 4) the rotor is provided with an annular conductor 60 having three spaced peripheral recesses 61. The contact 55 mounted on the stator is adapted to make continuous contact with the annular conductor irrespective of the peripheral recesses, but the contacts 56, 51, -and 52 are adapted to contact conductor except when in register with one of the three recesses. Contacts 56, 51, and 56 are connected around the edge of the switch stator to contacts 52, 53, and 54 respectively. Any other switching arrangement which is suitable for performing the necessary switching functions may be substituted for that above described.

As seen more clearly in Figure 6, one side of the supply line L is connected through the normal motor field 10 to the contact 55. From contact 55, the circuit may be traced to one of contacts56, 51 or 55, then to one of points 16, 11, or 18 of the control switch lli located at some remote point, and return to the other side of the supply line by way of ground.

An auxiliary circuit through field 10 may also be traced from the said side of the line through contacts 26 and return by way of ground. The circuit which when completed will produce a reverse torque on motor B, may be traced from the same one side of the supply line through reversing field 1|, and through contacts 21 to contact 51; from contact 51 to one of contacts 52,

53 or 54, thence to one of points 16, 11 or 15 on switch and return to the other side of the supply line by way of ground.

The control shaft A may have associated therewith any number of rotary switches 50 of a type similar to switch 56 which have their rotors secured to the shaft and have their stators mounted on some fixed support. The various electrical contacts on the stators of these switches may be connected to various circuit points in a radio receiver. With the contact points thus connected, it is clear that rotation of the member A operates to change the interconnection of these points, and in this way the. improved apparatus is useful for conditioning a radio set for operation on a selected one of several frequencies. It will be understood, however, that other and different control functions may be achieved by different connection with the device being controlled.

. Operation from one side of the supply line through the normal field 10, and contacts 56 and 16 to ground.

Note that at this instant nose 26 is engaging the intermediate cam surface and both contacts 26 and 21 are in open condition, thus rendering both the auxiliary and reversing circuits ineffective. Being energized through its normal field, the motor A beginsto rotate and through the worm gear arrangement drives the shaft IS in a direction which is counterclockwise as seen in Figure 1. Upon rotation of shaft IS, the cam surface 40 is brought into contact with nose-'28 and this closes contacts 21. This is of no effect, however, for at this time there is no path between contact 53 and ground, the remote control switch being on point 16.

As was before stated the control member remains locked in one position through the engagement between the cam 22 and-one of the tooth portions 23 on gear until the arm 24 has moved to bring pin 25 into contact with the walls of one of the recesses 2|; After gear 20 has been moved through rotation of the arm 24 and at or just before the time the'pin 25 has disengaged from the recess of gear 2|], the rotor of switch 50 will have been turned tobring one of recesses SI into register with contact 56 and the original energizing circuit will be broken; but before this time the lower cam surface 40* will have moved into engagement with nose 28 and contacts 25 will thus have been closed to maintain circuit. After the pin 25 has left the recess in gear 20, the intermediate cam surface 40' will come into engagement with the nose 28 to open contacts 26 and this operates to de-energize the normal field 10. Thus the motor is deenergized at a time after thecontrol member has reached its new position and has been locked there. It

is intended that the motor should coast to a stop while the intermediate cam surface 66'" is in engagement with nose 28, but if through motor momentum, movementshould continue until the higher cam surface 40 should come into engagement with nose 28,-this will operate to close a circuit which energizes the reversing field M. This latter circuit may be traced fromone side of the supply line through field 7i and contacts 21 to contact 51, and thence through contacts 52 and 16 to ground. I'his circuit will be completed only instantaneously, for once the circuit is completed, the reverse torque on the motor will quickly move the cam surface 48 back out of contact with the nose 28 to again open this circuit.

If then, the operator at the remote point should move control switch 80 back to point 11, a circult would be completed as before through the normal field ll] of the motor. .When the next succeeding of recesses Si in conductor ring 66 comes into register with contact 51, this original circuit is broken and energization of fleldlii continued through the auxiliary circuit until cam 40 operates to open contacts 25 after which the motor is stopped as before. With switch 50 arranged as herein described, this latter position of the control member will be removed 120 from the position first considered. A consideration of other positions to which the control member may be moved discloses that there are three angular positions of this member which correspond with each of the three points on the control switch as. In this particular embodiment it'is contemplated that the shaft C may be arranged to actuate the rotors of switches having four settings which givethe same electrical connections so that the control functions effected are repeated in each 120 of the shaft movement, but the arrangement may be otherwise if so desired. For exampia the gear 20 might be arranged with only four recesses instead of the twelve as shown; only one sector 59 might be used instead of the three as shown;

ring 50 might have but one recess BI; and a control switch of four points might be used instead of the three-point switch as shown. In

this example, each of the points of the control switch would have an individual control shaft position with which they correspond, and the operation of the motor deenergizing means for stopping the mechanism with the shaft, in a seis important that the radial position of the pinor projection 25 bear such relation to the periphery of gear 20 that this gear is moved the desired angular distance at one turn of the member on which this pin is carried.

While I have shown butone embodiment of the improved device, it is obvious that many other embodiments might be constructed, and many changes may be made in arrangement and construction without departing from the spirit of the invention.

The foregoing detailed description has been given for clearness of understanding only, and

no unnecessary limitations should be understood therefrom, but the appended claims should be construed as broadly as permissible in view of the prior art.

I claim:

1. Control apparatus of the character set forth comprising: a movable control member, an electric motor, drive means actuated by said motor for driving said member during periods in the operation of said motor but not during intervals between said periods, circuit means for energizing said motor for movement in one direction, cam means for deenergizing said motor after said member has been moved to a selected one of a plurality of positions and at a predetermined point in the operation of said motor during one of said intervals, and cam means operable subsequent to said first-mentioned cam means for energizing said motor for movement in a reverse direction whereby movement of said motor into the next of said periods of operation is prevented.

2. Apparatus as set forth in claim 1 inwhich each of said cam means have a common cam member which member is actuated by said motor.

3. Remote control apparatus of the character set forth comprising: a frame, a control shaft rotatably mounted in said frame, a gear member secured to said shaft and having peripheral recesses therein, an electric motor having a reversing field, a driving member rotatably mounted in said frame, said driving member having a projection adapted to engage said peripheral recesses in the gear member to rotate said gear member as said driving member is rotated, means connecting said driving member in mechanical connection with said motor, circuit means for energizing said motor for forward movement, means for deenergizing said motor after said member has been moved to a selected one of a plurality of positions and at a predetermined point in the operation of said motor during one of said intervals, said means including a cam member rotatable with said driving member, means operable only subsequently to the operation of said deenergizing means and in the event that said driving member moves on to a predetermined point in said interval for temporarily energizing the reversing field of said motor whereby movement of said motor into the next of said periods of operation is prevented, said means in.- cluding said cam member, and locking means for holding said gear motionless during said intervals, said locking means including a cam member rotatable with said driving member.

4. In a selective control system having a plurality of control positions, a reversible electric motor, a shaft driven by said motor, an intermittent motion mechanism actuated by said shaft a control member movable into said control positions and actuated by said mechanism, switch means for selecting any one of said control positions and energizing said motor, a cyclic switch aaoopaa operated Dy-said driven shalt, said cyclic switch having means for deenergizing said motor dur ins its first cycle of operation after attainment of said selected control position and for establishing a reversing circuit upon overrun of said motor.

5. In a selective control system having a plurality of control positions, a, reversible electric motor, a shaft driven by said motor, an intermittent motion mechanism actuated by said shaft, 9, control member movable into said control positions and actuated by said mechanism, switch means for selecting any one of said control positions and energizing said motor, a second switch operated by said driven shaft in timed relation with respect to said intermittent motion mechanism, and cam means associated with said second switch for deenergizing said motor after attainment of said selected control position and for establishing a reversing circuit upon overrun of said motor.

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