US2444448A

US2444448A - Planetary gear unit

Info

Publication number: US2444448A
Application number: US570952A
Authority: US
Inventors: Walter F Kannenberg
Original assignee: Bell Telephone Laboratories Inc
Current assignee: AT&T Corp
Priority date: 1945-01-01
Filing date: 1945-01-01
Publication date: 1948-07-06
Anticipated expiration: 1965-07-06

Description

MY 6, 1948- w. F. KANNENBERG 2,444,448

ARY GEAR UNIT /NVENro/Q W f' KANNE'NBERG UPA/EV July 6, 1948.

w. F."KANNENBERG 2,444,448

PLANETARY GEAR UNIT Filed Jan. 1, .1945 2 sheets-sheet 2 ATTORNEY Patented 1'illy 6, 1948 PLANETARY GEAR UNIT Walter F. Kanneuberg. Lyndhurst, N. J., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application January 1, 1945, Serial No. `570,952

5 claims. (Ci. `'i4- 291) This invention relates to circuit arrangements and apparatus for remotely controlling radio tuning devices and more particularly to gear mechanisms interposed between a. reversible motor and the tuning device whereby the speed ratio between the motor shaft and the tuning device is automatically` changed from high speed to low speed, or vice versa, for the purpose of rapidly locating the region of the critical tuning point and then slowly scanning the critical region, back and forth, to accurately locate the critical tuning point. I

A feature of the invention resides in a planetary gear mechanism whose ring gear is frictionally held to cause the planetary gear, under control of a sun gear on a driving shaft, to drive the tuning device through a driven shaft at slow speed back and forth over a, small area of the critical region` of the tuning range and,` by

high speed against the retarding effect of the friction applied to the ring gear.

Another feature comprises means for adjustably positioning said stop means whereby the tuning area traversed at low speed can be varied as desired.

The invention will be understood from the following descriptionand accompanying drawings,

Fig. 1 of which shows one embodiment of the invention;

Fig. 2 is a modification of the arrangement of Fig. 1; and

Fig. 3 shows a system for the remote control of thetuning device employing a gear mechanism of the typeshown in either Figs. 1 or 2, and also with means for indicating, at the remote control point, the setting or position at anylinstant of the tuning device.

As shown in Fig. 3 a device I adapted to `be tuned, by moving a plunger member 2 back and forth within a resonant chamber, is controlled by a. reversible motor 3 which is in turn conv trolled over a line Li from a remote control center, at the right of thebroken line AA', `by means of a pole changing switch 4. Motor 3 is 2 c coupled to and moves plunger 2 of the device through the medium of a driving shaft 5. a vgear mechanism Ii'according to the present invention, a driven shaft 'l and a rack and pinion arf rangement 8.

An adjustable resistance or rheostat R2 is associated with the tuning device I and has its contact arm 8 connected to and controlled by the plunger 2. A second line In `connects the rheostat Re with an indicating a-rrangement at the control point which arrangement comprises a meter IB, a line battery Il, a potentiometer P1, a rheostat or adjustable resistance R1, a small battery I2, and a switch I3. 'A description of the functions of `the indicating arrangement and im operation will be given hereinafter.

The gear mechanism 6 `will now be described by iirst referring to the arrangement of Fig. 1 which shows a planetary geark mechanism interposed between a driving shaft 5 and a driven shaft l. which as shown in Fig. 3, may control any desired device such as `an adjustable condenser, resonant chamber `or the like. Supported on thedriving shaft 5 and freely rotatable thereon by means of a spider `I4 is a ring gear I5 having internal gear teeth. Cooperating with the teeth of the ring gear, and also with a sun gear I 6 ixedly mounted on the driving shaft 5, is a so-called planet gear l1.` Frictional means, shown as a brake I8, engages 'the periphery of the ring gear and tends to resist its rotation and therefore the planetlgear Il `is caused to travel around the inside of the ring gear l5 in a well understood planetary manner. It will be noted r that vthe planet gear` Il isv rotatably supported on a crank member I 9 fixed to 'shaft 1 whereby planetary movement of gear Il causes shaft l to;revolve at a slower speed than the driving shaft 5, dependingon the ratio ofthe three gears I5, I6 and Il. Shaft Salso has'a reduced diameter threaded portion 20 which screws into a correspondingly threaded bore in shaft l whereby rotation of shaft .'I in either direction causes its lateral movement or displacement at a rate determined by the pitch ofthe thread. I Attached to the rim of ring gear I5 is an inverted slotted U-shaped stop member 2|, and mounted on the crank member I9 is an extension arm 22 of such dimensions that as the planetgear l1 moves `around the inside of gear IS'the arm extension will pass through the slotin member L 'I during a predetermined number of revolutions of the shaft l depending on the pitch` of the thread on the end of shaft! but when the lateral movement of shaft 1 moves the crank arm extension 22 so that it will not pass through the slot in the stop member 20 it'will abut the stop member. either to the/tight or lett of the slot, thereby preventing further movement of the planet gear with respect/to the ring gear Il. in the same direction/and therefore ring gear l5 and shaft l will rotate as a unit at the speed of shaft 5 againstftheretarding effect of brake Il.

The operation of the gear mechanism of Fig. 1 withthesystem of Fig. 3 is as follows: The

attendant at the control station desiring to effect control of the tuning device I which is associated with equipment, not shown, as for example radio apparatus, first closes switch I3 and then adjusts the meter I to obtain readings for both extreme positions of the plunger 2 of the tuning device by operating reversing switch 4 to a predetermined right or left position to cause the plunger to be moved to its extreme righthand position. Closure `of switch 4 energizes motor 2 which rotates shaft E together with sunA gear I6 which in turn causes shaft 1 to turn atr slow speed due to the action of planet gear I1 and at the same time :to cause lateral movement of shaft 1 and the crank arm I9 mounted thereon. The number of revolutions of shaft 1 at slow speed following closure of switch 4 will depend on the lateral displacement of crank arm extension 22 at the instant motor 3 is energized, but assuming shaft 1 is in such a lateral position at the start that the crank arm extension passes through the slotted stop member 2| twice before it abuts the stop member, then shaft 1, through the medium of rack and gear 8, will move plunger 2 slowly for a short distance to the right after which due to the crank arm exten-` sion 22 coming in contact with stop member 2| the plunger will be moved at high speed for the remainder of its travel thus cutting out the resistance of R2 from the line La at which time means, notk shown, as for example a slipping clutch, may be effective to prevent damage to the apparatus.

The attendant at the control vstation now observes the reading of meter I0, adjusts potentiometer P1 to set the needle at a predetermined maximum scale position indicated at B, and then operates switch 4 to its other or'second position thereby reversing motor 4 and its shaft 5 whereupon crankarm extension 22 of the gear mechanism backs away from its contact with stop member 2l and shaft 1 again rotates at slow speed in a reverse direction for the number of revolutions determined by the width of the slot in stop n member 2| after which extension' arm .22 again engages the stop member at the other side of the slot whereupon a one to one ratio between shafts and 1 is effected and plungerV 2 now rapidly moves to its extreme left position thereby including the total resistance of rheostat R2 in the line La. The attendant now adjusts rheostat Ri until the meter reads `at a predetermined low point, indicated at A onY the scale, which represents the resistance in series with batteryvII at the time. The intermediate points on the meter scale between points A and B now represent definite positionsof the plunger 2 of the tuning device. The circuit is now in readiness to check the operativeness of the tuning device which is accomplished bytransmitting a check wave of predetermined frequency. by means: not shown, and moving the plunger 2 back and forth by operating the motor first in one direction and then in the other until the critical tuning point is passed, then reversing the motor switch 4 whereupon the plunger will be moved at a reduced speed in the opposite d direction. By repeatedly `reversing the motor during the slow speed operation of the plunger the exact critical tuning point can be located. The position of the plunger 2 at this point will be indicated on the meter.

The modified` arrangement of gear mechanism 8, as shown in Fig. 2, will be understood from the following: As before, reversible motori drives the shaft 5 which carries the sun gear I6. Shaft -5 is loosely Journaled at 23 in the end of driven shaft 1 which in turn carries a crank arm I9 on which a planet gear I1 is free to rotate which gear cooperates with sun gear I8. An internal toothed ring gear I5 surrounds and cooperates with the planet gear Il. A brake or frlctional device I8 retards movement of the ring gear which gear is supported from the shaft 'I by a cup-shaped member 24 having a threaded opening in which a corresponding threaded portion 25 of shaft 1 revolves. `Two stop members 26 and 2l are adjustably fixed on the threaded portion 2liy and a cooperating stop pin 28 is located in the member 24. Upon rotation of shaft 5 planet gear I1 travels around inside ring gear I5 thereby turning shaft 'I at slow speed which due to its screw-threaded portion 25 causes lateral movement of the ring gear I5 and its supporting member 24 along the axis of the two shafts until stop pin 28 is moved into the path of one of the stop members 2B or 21, depending on the direction of rotation of the shaft 5. whereupon further movement, in the same direction, of planet gear i1 with respect to the ring gear is prevented and the two shafts rotate at the same speed against the friction of brake I8.

The stop members 26 and 21 are held in any desired position by means of set screws 29 and 30 whereby the slow speed movement of plunger 22 of the tuning device can be adjusted to any desired distance.

What is claimed is:

. l. In a planetary gear mechanism comprising` mutually cooperating sun, planet and ring gears, a driving shaft for rotating said sun gear, a driven shaft coaxial with the driving shaft, braking means for frictionally impeding said ring gear against rotation to cause planetary movement of said planet gear about said shaft axis, means comprising a crank member xedly mounted on said driven shaft and rotatably supporting said planet gear for causing said planetary movement to rotate said driven shaft, screw-threaded means responsive to rotation of said driven shaft for axially displacing said driven shaft with respectA to said ring gear, and other means `comprising stop members fixedly associated -with said driven shaft and ring gear kadapted to cooperate in response to predetermined axial displacement of said driven shaft in either direction, depending on the direction of rotation of said driven shaft, to effect a direct coupling between said two shafts.

2. In a planetary gear mechanism comprising mutually cooperating sun, 'planet and ring gears, a driving shaft for rotating said sun gear, a driven shaft coaxial with the driving shaft, braking means for frictionally impeding said ring gear against rotation to cause planetary movement of said planet gear about said shaft axis in response to rotation of said driving shaft, means comprising a crank arm 'xedlymounted on said driven shaft and rotatably supporting said planet gear for causing rotation of said driven shaft responsive to planetary movement of said planet gear thereabout. and other means comprising stop members xedly associated with said driven shaft and ring gear adapted to cooperate after a predetermined number of revolutions of said driven shaft, in either direction, to cause said driven shaft to rotate at the same speed as the driving shaft against the impedng effect of said braking means on -the ring gear.

3. In a gear drive mechanism a driving shaft, a sun gear fixed on said driving shaft, a driven shaft coaxial with said driving shaft, a crank arm mounted on said driven shaft, a ring gear, a planet gear rotatably mounted on said crank arm and engaging both said sun and ring gears, braking means for frictionally retarding rotation of said ring gear to cause rotation of said driven shaft in .response to rotation of said driving shaft, means responsive to rotation of said driven shaft foi` laterally displacing said driven shaft and ring gear with respect to each other in either direction depending upon the direction of rotation orf said driving shaft, and stop means associated with both ring gear vand driven shaft adapted to engage each other upon a predetermined lateral displacement of said driven shaft to cause said driving and driven shafts to rotate at the same speed against the impeding effect of said braking means on the ring gear.

4. In a gear drive mechanism, a driving shaft, a sun gear fixed thereon, a ring gear rotatably supported on said driving shaft, a driven shaft coaxial with said driving shaft, a crank arm mounted on said driven shaft and rotatable therewith, a planet gear rotatably mounted on said crank arm and engaging both said sun and ring gears, braking means for frictlonally retarding rotation of said ring gear to cause rotation of said driven shaft in response to planetary movement of said planet gear, means comprising a screwthreaded portion of said driving shaft cooperating with a correspondingly threaded bore in said driven shaft to axially displace said driven shaft with respect to said ring gear upon rotation ofV 6 said driven shaft, a pair of axially spaced stop members on said ring gear, and an extension of said crank arm adapted to engage one or the other ofsaid members upon axial displacement of said `arm a predetermined amount, in either direction, to effect a one-to-one speed ratio coupling between said driving and driven shafts.

5. In a planetary gear mechanism, a driving` shaft, a sun gear fixed thereon, a driven shaft coaxial with said driving shaft, a ring gear coaxial with said shafts, a supporting member for said ring gear screw-threadedly mounted on said driven shaft, a crank arm fixed on said driven shaft and rotatable therewith, a planet gear r0- tatably mounted on said crank arm and engaging both said sun and ring gears, braking means for frictionally retarding rotation of said ring gear to cause rotation of said driven shaft in reV sponse to planetary movement of `said planet gear, and to thereby cause the axial displacement of said driven shaft with respect to said ring gear supporting member, a pair of adjustable axially spaced stop members on said driven shaft and a corresponding pair of stop members on said ring gear supporting member, said pairs of stop members being so positioned that axial displacement of said driven shaft in either direction a predetermined amount causes one member of each pair of stop members to abut each other to effect a. one-to-one speed ratio coupling between said driving and driven shafts.

WALTER F. KANNENBERJG. I

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

vUNI'I'ED STATES PATENTS Olson Aug.; 18, V1942