US2392320A - Remote control actuator - Google Patents

Description

Jan. 8, 1946. L HEGY 2,392,320

REMOTE CONTROL ACTUATOR Filed Oct. 4, 1944 2 Sheets-Sheet 1 /8 i Q Q INVENTOR. LOUIS HEGY Ja s, 1-946. L; HEGY zwzazo REMOTE CONTRCSL ACTUATOR Filed-Oqt. 4, 1944 2 Sheets-Sheet 2 INVENTOR. LO U I S H E G Y Patented Jan. 8, 1946 REMOTE CONTROL ACTUATOR Louis Hegy, Burbank, Calii'., assignor to Bendix Aviation Corporation poration oi' Delawar South Bend, Ind.,' a core Application October 4, 1944, Serial No. 557,197 i "9 Claims. (01; ire-23's) This invention relates to remote control actuators for positively moving a mechanism-into and holding it in desired positions, and relates more particularly to electrically actuated devices of this type although it is not necessarily limited thereto.

An object of the invention is to provide a compact, simple and reliable actuator.

Another object is to provide a compact simple and reliable reversible actuator capable of movmg in either direction into desired positions but which is positively locked against movement by extraneous forces out of either extreme position.

Another object is to provide an electric actuator mechanism in which the driving motor has no load thereon at the time of starting so that a motor having low starting torque can be employed without the use of a clutch. 1

Another object is to provide an electric actua tor in which the load on the motor become ,pmc:

tically nil at the completion of a movement so that the shutofi switch for stopping the motor does not have to break a heavy current.

Another object is to provide an electric actuator having a particularly durable and reliable switch mechanism for controlling the motor.

Other more specific objects and features of the invention will become apparent from'the detailed description to follow of a specific embo'diment thereof.

Briefly, my actuator comprises a compact casing containing two parallel shafts, one of which actuates the driving element of a novel Geneva movement, and the other of which is actuated by the driven element of the Geneva movement. The driving element of the Geneva movement is connected through a speed reducing gear train to an electric motor mounted on the casing, and the gear train comprises aplurality of gears rotata-bly-mounted onthe two shafts withinthe caslng. To automatically stop the motor after completion of each cycle of the Geneva movement a selector switch is mounted in a separate chainher in the housing opposite one end of the driven shaft, the movable member of the switch being Fla. 1 is a plan view of one embodiment of the invention;

Fla. 2 is a section taken along the line 11-11 0! Fig. 1;

Fig. 3 is a section taken along the line III-III 0 s k Fi 4 is a section taken alone the line Iii-IV of Fig. 2; and

Fig. 5 is a schematic diagram of the electrical circuit of the device.

Referring to Figs. 1 and 2, the device comprises a casing containing all the working elements with the exception of the electric motor.

The casing is made in three sections it, ii, and

i2; Section it consists of an end wall it and a peripheral wall it having a hat upper edge against which a flange it, projecting from the bottom wall it of the section it, seats. The section H, in addition to the bottom wall it, includes a peripheral wall it having a flat upper edge against which the cover plate (section i2) fits. Screws l8 extend through the cover plate l2 and, the peripheral wall of section it into the lower section I, to detachably connect the difierent parts of the casing'together. An electric motor is attached as by screws to a face provided therefor on the exterior surface of the peripheral wall ill of'the lower section of the case. The shaft ii of the motor projects through the wall of the casing and has a worm 22 on its end which meshes with and drives a worm wheel 23.

Referring particularly to Fig. 2, the worm wheel 23 is formed integrally with a pinion it, and the assembly is rotatably supported on a shaft 25 journalled in bearings 2'8 and ii in the casing walls i3 and i6 respectively. The pinion 2d meshes with and drives a spur gear 28 which is formed integrally with or is rigidly secured to a pinion 29, the assembly being rotatably supported by a shaft 30 which is iournalled in hearings 3i and 32 in the casing Walls 93 and i6. 29 meshes with a spur gear 533 which is fixed to the shaft '25 as by a pin 34, although it-is not essential to the operation of the device that the shaft 25 rotate with the gear 33. However, the pin 34 serves to fix the gear 33 to the shaft 25 and to prevent its escape therefrom during handling and assembly. The-desired longitudinal, or axial, positions of the gears on shaft 25 are determined by the fact that the assembly of elements fills the space between the bearings 28 and 21.

The driving mechanism of the Geneva.m0vement is mounted on the gear 33 and it cooperates with adriven element keyed or locked to' Th pinion.

I the shaft 89, which is the driven shaft and is extended through the wall I! of the casing and splined or otherwise shaped for connection to a suitable driven element.

Referring now to Figs. 2 and 3, the driving elements of the Geneva movement comprise a disk 31, formed integrally with or secured to the upper face of gear 33 and a crank pin 38 projecting upwardly from the gear at a point spaced radially outwardly from the disk 31. The disk is provided with an arcuate recess 31a adjacent the crank pin. The driven element of the Geneva movement comprises a sector 39 having a hub 39:: pinned to the shaft 39. The sector 39 has a central radial slot 991: dimensioned to slidably receive the crank pin 38 and has a pair of arcuate recesses 39c and 3911 in its rim on each side of the slot. The sector 39 (Fig. 2) is thicker than the disk 31 and has a projecting flange 39c which overlaps the disk for the purpose of extending the length of the slot 38b. The recesses 39c and 39d may extend through the flange 39c as shown in Fig. 3. but this is not essential.

Fig. 3 shows the Geneva mechanism in one extreme position, in .which the disk 81 has entered the recess 39d in the sectorand is contacting both ends of the sector to thereby prevent angular movement of the sector in either direction. However, when it is desired to rock the sector 39 clockwise into its other extreme position, the gear 33 is rotated in counterclockwise direction by suitably energizing the motor 39. Initial movement of the gear causes the crank pin 98 to enter the slot 391). At first, the motion of the crank pin is parallel to the slot, so that there is substantially no load on the motor other than that necessary to overcome the friction of the gear train. As the pin 38 revolves, its direction changes and it bears against the lower edge of the slot 3% to shift the sector clockwise. This movement is permitted by the fact that counterclockwise rotation of the disk 31 carries the leading end of the recess 81a into the recess 3901. The movement continues until the pin 88 has been carried into and then out of the slot 39b, at which time the disk 81 will have engaged the recess 390 to lock the sector against movement by extraneous forces.

It is important to note that it is not at all necessary to accurately time the stopping of the motor 28 and the gear 33 driven thereby. The gear 33 could rotate clockwise through nearly 240 after the pin 38 leaves the slot 3% .without changing the position of the sector 29. This slimmates the necessity of employing any brake or smcial mechanism for quickly stopping the motor, because, with the gear reduction shown, it would be quite impossible for the mechanism to coast far enough to carry the gear 33 beyond its limit of free travel. Regardless of how far the crank pin 38 travels after leaving the slot 39b, it will always re-enter the slot when the movement of the gear 33 is reversed, because the sector 3t will be retained in proper position for.

re-entry of the pin 38 into the-slot 3% by the disk 31.

An important feature of the invention is the making of the recesses 39c and 89d of a smaller radius of curvature than the radius of curvature of the disk 31, so that the latter contacts only the ends of the recess in looking position. This makes it possible for the disk to engage with both ends of the recess just as the pin 39 leaves the slot In a conventional Geneva mechanism the reaaaasao cess 99c and 99d would have the same radius as the disk 81. With the conventional construction the parts must be so spaced and positioned that when the pin 38 leaves the slot 39b the end of the recess 31a is at the mid-point of the recess 39d. with such an arrangement, reverse movement of the sector 39 can be controlled only with considerable difficulty, because the mid-portion of the recess 39d is moving substantially parallel to the adjacent portion of the disk 38 (the adjacent portion being the lower end of the recess 81a) and'unless all clearance is eliminated between the recess 39d and the disk 31, back lash is inevitable. Furthermore, a powerful wedging force is exerted, tending to bind the shafts of the sector 89 and the disk 31 in their bearings and jamming the mechanism.

In contrast to the conventional mechanism, in the present mechanism, in which the recesses 39c and 3911 have a substantially smaller radius of curvature than the disk 31, the parts can be so proportioned that the disk 31 contacts both ends of the recess 39b or 390 at the time the pin 38 leaves the slot 8912. This makes it possible to reduce the back lash between the sector 39 and the disk 31 to a small value without employing tolerances that are difilcult to meet in manufacture, and prevents the development of powerful wedging forces that would tend to bind the members in their bearings and thereby jam' the device. Various control circuits may be employed with the mechanism described, but a particularly desirable one is shown in the drawings and will be described with particular reference to Figs. 2, 4, and 5.

Referring first to Fig. 5, the motor is illustrated as having an armature 20a and a pair of field windings 29b and 290, which field windings are oppositely poled so that when current is supplied through one, the motor runs in one direction, and vice versa. As indicated by the arrows,

when current is supplied through field winding 20!), the motor runs in such direction as to cause the shaft 39 to be rotated clockwise, and when the current is supplied through the field winding 200, the motor runs in the opposite direction, which results in movement of the shaft 39 counterclockwise, the direction being wlth reference to the views of the apparatus in Figs. 3, 4, and 5. Circuits to the motor through one or the other of the field windings 29b and 29c are completed from a battery 55 through a manual control switch 544 and switches automatically controlled by the shaits 39 and 25. The arrangement is such that when the manual switch 5c is thrown to the left on to a contact 53, a circuit is completed to rotate the shaft 39 counterclockwise, and when the switch 55 is thrown to the right onto a contact 52, a circuit is completed to rotate the shaft 30 clockwise.

Referring to Figs. 2 and 4, the automatically controlled switches comprise a selector switch 69 actuated by the shaft 39, and a snap action switch 5i actuated by a cam 62 on the shaft 25. The switch 8! is closed when its plunger 63 is de pressed by the cam 62 and opens when the cam aseasao adapted to contact other contacts supported on the insulating ring. The segment 65 always contacts the contact 65a, and contacts contact 650 in one extreme position of shaft 36 and contacts contact 65b in the other extreme position. The conductive segment 6'! always contacts contact Ill and contacts contact 69 in one extreme position and contacts contact H in all positions except said one extreme position. Segment 68 like-' wise always contacts contact 13, but contacts contact ll only in extreme clockwise position and contacts contact I2 in all positions except the extreme clockwise position.

The switch arrangement is such that the selector switch 6|], together with the manual switch 54, completes a circuit to start the motor running in direction to move the shaft 36 out of its existent position and into its other extreme position, and the snap switch 6| functions to open the circuit to the motor when the latter has moved far enough. This eliminates the interruption by the selector switch 60 of any currentcarrying circuit, thereby prolonging the life of the contacts. The snap switch 6| which is of conventionaldesign and need not be described, can be of a type adapted to give long service even though it breaks current of substantial value.

Fig. 5 shows the switch system in the condition existent when the shaft 36 has been moved into extreme counterclockwise position as shown in Figs. 3 and 4. It will be observed that the only circuit from the battery 55 extends through the manual switch. 54 and fixed contact 53 to con tact l6 and thence through segment 61 to contact 69. A circuit is also completed from contact 69 to one terminal ofthe snap switch 6| and to the contact 14. However, no current can flow, because the switch 6| has just been opened by the cam 62, and the contact 14 is out of contact with the segment 66. Hence, the motor is de-energized.

Now, assume that it is desired to shift th shaft 30 clockwise into its other extreme position. To do this, the manual switch 56 is thrown onto the contact 52, completing a circuit from the battery 55 tothe contact 13 of the selector switch and through segment 68 to contact 12 and armature a to ground, starting the motor in such direction as to rotate the shaft counterclockwis and the shaft 36 clockwise. Initial motion of the shaft 25 in counterclockwise direction causes the cam 62 to depress the plunger 63 and close the switch 6|. duces no new path for current fiow immediately. After clockwise motion of the shaft has continued for some time, however, the segment 68 closes with the contact .14, completing a path for current fiow from the contact 13 through segment 68, contact 14, and through the now closed switch 6| to contact 65a and segment 65. By this time, the segment 65 has moved out of contact with contact 650 and into contact with contact 65b completing a new path for current flow to the field windinglllb. Shortly thereafter, the original path for current flow through contact 12 is broken by the movement of segment 68 clear of contact 12. Because of the fact that a parallel circuit is completed through the switch 6| at the time segment 68 leaves contact 12, there is no arcing at the latter contact. The movement continues with current being supplied through contact 13, segment 68, contact 14, switch I 6|, contact 65a, segment 65, and contact 6512 until switch 6| is again opened by the cam 62.

However, this prois again thrown to the left into engagement with .thence through the field winding 20b and the I wall and having a .shaft extending through said.

contact 53. Thereupon a circuit will be completed from contact 53 through contact 10, segment 6'! and contact 1| through the motor field 20c and armature 20a, to start the motor in the reverse direction, which motion will continue until the parts again reach the position shown in Figs. 4 and 5.

An additional advantage of employing the camactuated switch 6| in conjunction with the selector switch 60 is that the energization of the motor'can be maintained until after the pin 38 has left the slot 3%, thereby positively assuring full movement of the sector 39 and the shaft 36. Obviously, if switches actuated by movement of the shaft 36 alone were employed, the contacts that stop the motor would have to be opened slightly before the shaft 30 reaches its end position, and the momentum of the motor would have to be relied upon to carry the segment 39 into its final position.

It is apparent that the feature of the invention involving th deep recesses 39c and 39d, for enabling contact of the disk 31 with the shoulders at both ends of one of the recesses at the time the pin 38 leaves the slot 39b, is not limited to the two-position reversible mechanism, which is shown for purpose of illustration. This feature.

ing more than two positions of the driven memher and in systems which are notreversible.

Likewise, the use of the auxiliary switch 6| actuated by the driving shaft is useful in unidirectional systems and systems having more than two positions of the driven member.

Obviously, the construction of the selector switch 60 would have to be modified in a system having more than two positions, but such modification is Well within the capabilities of those still in the art.

"Various other departures from the exact construction shown can be made without departing from the invention which is to be limited only to the extent set forth in the appended claims.

Iclaim:

1. A mechanism of the type described-comprising: a casing having first and second opposed walls; first and second parallel shafts extending between and journalled in said walls, said second shaft extending through said first wall for connection to a device to be actuated; a gear train for rotating said first shaft comprising intermeshed gears on said shafts and including a final driven gear on said first shaft; a third wall inmounted against the outer surface of said third third wall into said casing, with gear means on said shaft engaging a gear of said gear train for driving it; a crank pin and a concentrically positioned disk extending axially from one face of said final gear, said disk having a recess in its rim adjacent said crank pin; a sector secured to said second shaft and having a radial slot adapted to be engaged by said crank pin and having recesses in its rim on each side of said slot adapted to receive said disk for locking said sector when said crank pin is out of engagement with said slot and cooperating with the recess in said disk to permit movement of the sector by the crank pin when the latter is positioned in said slot. a

21 A mechanism of the type described comprising: a casing having first and second op-, posed walls; first and second parallel shafts ex tending between and ioumalled in said walls, said second shaft extending through said first wall for connection to a device to be actuated; a gear train for rotating said first shaft comprising intermeshed gears on said shafts and including a final driven gear. on said first shaft; a third wall interconnecting said first and second walls; a motor mounted against the outer surface of said third wall and having a shaft extending through said third wall into said casing, with gear means on said shaft engaging a gear of said gear train for driving it; a crank pin and a concentrically positioned disk extending axially from one face of said final gear, said disk having a recess in its.

rim adjacent said crank pin; a sector secured to .said second shaft and having a radial slot adapted to be engaged by said crank pin and having recesses in its rim on each side of said slot adapted to receive said disk for locking said sector when said crank pin is out of engagement with said slot and cooperating with the recess in said disk to permit movement of the sector by the crank pin when the latter is positioned in said slot; additional wall means exterior of said second wall and defining therewith an auxiliary chamber, said second shaft projecting into said auxiliary chamber, and switch means in said auxiliary chamber actuated by said second shaft for opening the circuit of said motor when said sector moves into locked position.

3. A mechanism of the type described comprising: a casing and first and second parallel shafts within said casing; a reversible electric motor; a concentrically positioned disk on said first shaft having a recess in its rim; and means coupling said disc to said motor for rotation thereby; a crank pinconnected to said disc in radially outwardly spaced relation with respect to the recess in said disk; a sector secured to said second shaft in the plane of said disk and crank pin and having a radial slot adapted to be engaged by said crank pin and having recesses in its rim on opposite sides of said slot, said recesses being adapted to receive said disk for locking said sector when said crank pin is out of engagement with said slot, and cooperating with the recess in said disk to permit movement of the sector by the crank'pin when the latter is positioned in said slot; switch meansactuated by said second shaft comprising two pairs of contacts and means actuated by said second shaft for closing one pair of contacts in all positions of said sector save one extreme position thereof and closing the other pair of contacts in all positions of said sector save the-other extreme position thereof, and means for supplying current through said first pair of contacts for driving said motor in one direction and separate means for supplying current through said second pair of contacts to drive said motor in the other direction.

a 4. A mechanism of the type described comprising: a casing having first and second opposed walls; first and second parallel shafts extending between and journalled in said walls, said second shaft extending through said first wall for connection to a device to be actuated; a gear train for rotating said first shaft comprising intermeshed gears on said shafts and including a final driven gear on said first shaft; a third wall interconnecting said first and second walls; a

motor mounted inst the outer surface of said third wall and having a shaft extending through said third wall into said casing. with gear means asoasao 'rim' adjacent said crank pin; a sector secured to said second shaft and having a radial slot ada ted to be engagedby said crank pin and having recesses in its riin on each side of said slot adapted to receive said disk for locking said sector when said crank pin is out of engagement with said slot and cooperating with the recess in said disk to permit movement or the sector by the crank pin when the latter is positioned in said slot, said sector having an edge portion of the same axial thickness as said disc cooperating with said disc, and a radially projecting portion adapted to overlap said disc and the length of said slot, and said pin being of greater axial dimension than said disc for engagement with that portion of said slot extending through said flange.

5. A mechanism of the type described comprising: rotary driving and driven members having spaced-apart, parallel axes of rotation, the driven member having a radial slot and the driving member having a pin element adapted to move into and out of said slot and rock said driven member through a fixed angle in response to rotation of said driving member, and means for locking said driven member against angular motion While said pin is out of said slot, said locking means comprising interengaging disk elements on said driving and driven shafts, said disk elementshaving peripheral recesses therein interengaging with each other to permit rotation of said driven member and said driving member when said pin is in said slot, the recess in the disc element of said driven member being relatively deep with respect to the curvature of the disk on 6. In a mechanism of the type described, driving and driven members rotatable about spaced, parallel axes,'and a Geneva mechanism intercoupling said members, said Geneva mechanism comprising: a radially slotted element on the driven member, a pin element on the driving member adapted to enter and then leave said slot in response to rotation of the driving member and rotate the driven member through a fixed angle while said pin engages saidslot, a recessed disk element on the driving member and a recessed element on the driven member, the recess in said recessed element defining a pair of spaced shoulders adapted to be engaged by said disk element in response to rotation of saiddriven member suflicient to carry said pin out of said slot, and said recess being of such depth as to provide substantial clearance with said disk element when the latter engages said shoulders, said disk and recessed element being so proportioned and oriented with respect to said pin and slot that said disk element is in engagement with both said shoulders when said pin element is out of engagement with said slot.

7. A mechanism of the type described comprising: rotary, driving, and driven elements rotatable about spaced, parallel axes, a pin element eccentrically disposed on said driving element. a radially slotted element on said driven member adapted to be engaged by said pin element and rotated thereby through a fixed angle in response to rotation of said driving member, said driven member having a recess in its periphery angularly spaced from said slot and defining a pair of shoulders of equal radius less than the radius r of the outer end of said slot, a disk element on said driving member of radius such as to engage both said shoulders when the latter are symmetrically disposed on opposite sides of the planeof said axes, said disk having a recess for passing one of said shoulders during rotation of said driven member by said pin element and said recess that defines said shoulders'being of such depth as to permit rotation of said disk element into engagement with both said shoulders during driving engagement of said pin element with said slotted member.

8. A mechanism of the type described comprising: rotatable driving and driven members, and a Geneva mechanism intercoupling them for rotating said driven member through a fixed angular distance between two predetermined positions in response to successive rotation of said driving member in opposite directions, said driving member having a range of free movement beyond said predetermined positions of said driven member, a reversible electric motor connected to said driving member for driving it, said motor having one circuit for rotating it in one direction and another circuit for rotating it in the opposite direction, a selector switch actuated by said driven 1 member to open and close contacts according to the position of the driven member, a source of energizing current, a master switch for selectively completing either one of two energizing paths to said selector switch, an auxiliary switch, said selector switch including contact means for closing a first circuit from one of said paths directly to one motor circuit and closing a second circuit from said other path through said auxiliary switch to the other motor circuit while said driven member is in a first range of movement extending from one predetermined position, said selector switch including contact means for closing athird circuit from the other or said paths directly to the other motor circuit and closing a fourth circuit from said one path through said auxiliary switch to said one motor circuit while said driven'member is in a second range of movement extending from the other predetermined position and overlapping said first range, and means driven directly by said driving member for closing said auxiliary switch during movement of the driving member throughout its driving engagement with said driven member whereby said auxiliary switch always interrupts the energizing circuit of the motor at completion of movement of said driven member in either direction.

9. A mechanism of the type described comprising: rotary driving and driven members having spaced-apart parallel axes of rotation; cooperating means on said driving and driven members for rotating said driven member through a fixed angle in response to rotation of the driving memher between two predetermined angular positions; and means for locking said driven member against angular motion while said driving member is beyond one of its said predetermined angular positions, saidlocking means comprising cooperating elements on said driving and said driven members; the element on said driven member having a pair of arcuately-spaced shoulders of the same radius and the element on the driving member having an arcuate surface concentric with respect to its axis and of radius and arcuate length such as to simultaneously engage both said shoulders during rotation of said driving member through a predetermined angle beyond said one predetermined angular position, said arcuate surface terminating abruptly at one end and said element on the driven member having a recess between said shoulders deep relative to the curvature of said arcuate surface; said elements being so oriented relative to said means for rotating said driven member, so that said arcuate surface completes contact with both said shoulders as said driving member completes its movement into its said one angular position.

LOUIS HEGY.

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