US2241013A - Speed change for recording apparatus - Google Patents

Description

' May 6, 1941. P. s. GAY V i 2,241,013

srmsn cmmem. son RECORDING APPARATUS Filed Oct. 8, 1940 I s Sheets-Sheet 1 INVENTOR.

ATTORNEY.

May 6, 1941. P. s. GAY 2,241,013

SPEED CHANGE FOR ancoamm APPARATUS Filed Oct; 8-, 1940 s Sheets-Sheet s Patented May 6, 1941 UNITED STATES PATENT OFFICE sraan CHANGE roa RECORDING arranarus corporation of Michigan Application October 8, 1940, Serial No. 360,288

9 Claims.

This invention relates to record apparatus which involves the use of a turntable upon rotation of the turntable in accordance with dif- 10 ierent records where the records have been cut at difierent speeds or where the records have been manufactured so as to be operated at different speeds. Thus in certain types of sound recording work, a turntable is operated at a speed of only 33% revolutions per minute instead of the normal 78. A speed adjustment of the type herein described may be utilized for the purpose of adjusting the speed of rotation of the turntable to accommodate records which should be played at different speeds.

Such "fast and slow adjustments may, of course, be used for other purposes although primarily it has been designed by me for use in connection with the purposes above mentioned.

Thus, for instance, in apparatus now on the market of the type described in my application above mentioned, the same turntable and operating mechanism therefor is used both for cutting the record and for playing the record back.

When a record iscut on the turntable the power demand is"comparatively much greater than when a record is being played back, since the cutting stylus must actually remove material from the surface of the disk in order to create the groove, while in playing back the recording needle need merely follow the groove which has already been cut.

Such difierences in power demand cause differences in the actual load upon the turntable and hence upon the operating means therefor, tending to cause a difference in speed. Such difference in speed may, under certain circumstances, be sufiicient to actually change the quality of the voice during the playing back of the record; that is, the record, when played back when only the transcription needle need follow the groove, is under a lighter load and hence the tendency is for it to rotate faster, thus raising the pitch of the voice somewhat."""Wh en the turntable is slowed down to a predetermined degree, the quality or timbre of the recorded voice is once more recognizable.

My present invention may be used for chang- (Cl. lb-190) to correct for these factors; that is, the turntable is set so that it will normally be rotated at a slightly greater speed when a record is being out than when it is being played back.

The differences in the speed adjustment need not be. great but should in the ordinary case be only suflicient to compensate for the difference in load.

Thus in accordance with my invention when a record is being cut on'the turntable, the speed adjustment should be set at fast or cut. The added load on the turntable owing to the cutting operation would then tend to slow down the operation of the turntable. If the record were then played back with the ordinary recording needle while the speed adjustment is at the same setting, then, owing to the decreased load, the turntable would be permitted to rotate faster and thence change the pitch of the recording. Accordingly, to compensate for this the operator may move the speed adjustment over to slow or play, thus slowing down the turntable for playing the record.

The speed adjustment should be such in this case that the turntable, when the record is being played, would then be rotating at the same speed as it was rotating when an actual cutting was being made and thus by this type of adjustment the quality of the record is not changed during the playing back by reason of any variations in the speed of rotation of the turntable.

The particular type of speed adjustment of my device lends itself readily to an adjustment for stopping the turntable while the operating apparatus' therefor remains in motion. This materially reduces the masses of the members which must be brought to a stop.

Ordinarily, in order to stop the rotation of the turntable the motor and other members operating the same must be stopped. The speed adjustment of my invention may be arranged to have a stop adjustment so that the turntable is disengaged from the operating mechanism therefor and only the mass of the turntable need be brought to a stop.

Preferably, my invention is utilized in connection with and incorporated in the principle of power transmission described in my application above mentioned; that is, the motor spindle is not directly connected to the turntable but instead frictionally bears against an idler which is caused to rotate thereby, the said idler contable, thus transmitting the motion from the ing the speed of rotation of the turntable so as spindle of the motor to the turntable,

The operation of my invention depends upon the changing of this idler connnection between the spindle of the motor and the flange of the turntable and the utilization of at least a number of different idlers which may be successively placed in operative position between the spindle of the motor and the turntable.

In order to bring the turntable to a stop, I may also arrange these idlers in such a position that at one setting thereof neither of the idlers is operatively engaged between the spindle of the motor and the turntable.

An important object of my invention, therefore, is to so arrange the driving connection between the operative means and the turntable of the recording apparatus that the speed of rota tion of the turntable and recording apparatus may be varied.

Still another object of my invention is to so arrange the power connection between the driving means and the turntable that the said driving connection may selectively be removed from between the spindle of the motor and the turntable, thus permitting the turntable to be brought to a stop without stopping the motor or other operating parts for the turntable.

Another more specific object of my invention is to arrange a pair of idlers on a single floating carrier in such a manner that different idlers may selectively be brought into operative engage-' ment between different portions of the motor spindle and the turntable to effect different speeds of operation or rotation of the turntable.

These and other objects of my invention will in part be apparent and in part pointed out in the following description and drawings in which:

Figure 1 is a view in perspective partially broken away of the turntable operating apparatus embodying the subject matter of my invention.

Figure 2 is a top view of a portion of the construction of Figure 1 showing the members in the position of Figure 1.

Figure 3 is a view corresponding to Figure 2 showing a different position of the members thereof.

Figure 4 is a view corresponding to Figures 2 and 3, showing the stop position of the members thereof.

Figure 5 is a cross-sectional view taken along line 5 of Figure 3.

Figure 6 is a cross-sectional view taken on line 6-6 of Figure 5.

Figure 7 is a'view corresponding to that of Figure 2 showing a slightly modified method of operating the idler change mechanism.

Figure 8 is another view corresponding to the view of Figure 2 showing a still further modified form of the idler change mechanism.

Figure 9 is a cross-sectional view taken on line 9-9 of Figure '7.

Figure 10 is a cross-sectional view taken on line Ill-40 of Figure 8.

Referring now to Figure 1, I have here shown in somewhat schematic arrangement the operating mechanism for use in connection with the turntable which is utilized for both cutting records and playing the records back. This turntable operating mechanism is'constructed in substantially the same manner as that of the record-. ing apparatus described in my prior application above mentioned, and comprises a base plate carrying a hollow post 2| in which is rotatably journalled a post 22 which carries a platform 23 upon which is mounted a playback arm 24.

The playback arm 24 is rotatable in a vertical plane about the platform 23 and the platform 23 is rotatable in a horizontal plane with respect to the base plate 20 so that the playback arm which normally carries a playback needle may be readily placed in operative connection with a recording disk mounted on the turntable and so that it may readily follow a groove in the recording disk."

The base plate 20 also carries a hollow post 26 in which is rotatably and slidably journalled the post 21 to which is secured the platform 28. The cutting arm 29 is pivotally mounted by means of the members 30 upon the platform 28 so that the cutting arm may be rotated in a vertical plane. The platform 28 may, as has above been mentioned, be rotated in a horizontal plane and thus the cutting arm may be placed in operative connection with a recording disk upon the turntable.

The cutting arm is driven by means of the arm 3| and the follower 32 which may be releasably engaged with the screw 33 which may be driven from the motor or, in the preferred form, from the turntable. The operation of the cutting arm and a full description of all of the members thereof is set forth in my application Serial No. 320,823, filed February 26, 1940 and forms no part of the present invention.

It is sufficient to note that the cutting stylus of the cutting arm when the stylus is placed upon a disk on the rotating turntable offers sufflcient resistance to the rotation of the turntable to tend to slow the turntable down, thus makin it desirable to use the speed adjustments of the type hereinafter to be described.

The turntable is rotatably mounted on the spindle 4 l The said turntable has a downturned flange 42 against which the operative connection between the motor and the turntable may bear.

The motor (not shown) is secured beneath the mounting plate 43 which in turn is mounted on the base plate 20. The motor spindle 44 projects through an opening in the mounting plate 43 above the surface of the base plate 20. The specific mounting of the motor and the arrangement thereof to reduce power pulses and consequent shocks therefrom is described in my application above mentioned and a description thereof is not necessary for an understanding of the present invention.

In my application aforementioned I describe the manner in which motive power is transmitted from the spindle 44 through the idler mounted upon its floating mounting to the flange of the turntable. In the present application two such idlers and 5| are shown. Each of these idlers has a tire, 52 and 53 respectively, of resilient compressible material preferably rubber and adapted to transmit power by friction.

Each of the idlers is mounted, as is more specifically hereinafter described, upon the floating idler carrier 55. The floating idler carrier 55 is held upon the mounting plate 43 by means of the washer 56 indicated by dotted lines in Figure 2 and more clearly shown in cross-section in Figure 5. The washer 56 is fixedly positioned upon the pin 51 by means of the lock nuts 58. the pin 51 being Supported by the mounting plate 43.

The opening 59 in the floating idler mounting 55 is larger than the diameter of the pin 51 so that the floating mounting 55 can accommodate itself to the position of the idler and so that the floating mounting spring may also exert pressure upon the idler for the purposes described in position for engagement of the idlers.

my application above mentioned and for the more specific purposes hereinafter described.

A spring 50, captured at one end at 6| in the an opening II in the floating idler mounting in order to provide a point about which the floating idler mounting may rotate. The opening II in the floating idler mounting is slotted to permit the floating idler mounting to move slightly during the adjustment of the idlers.

Likewise thefact that the opening 59 is muc larger than the opening 51 permits the floating idler mounting to adjust itself to the appropriate As is seen more particularly in the cross-sectional view of Figure 5, idler 5| is rotatably mounted on the bearing 00. The said bearing 80 is itself rotatably mounted on the pin 8| which is secured to the floating idler mounting 55. The pin 8| has a washer 82 secured thereto and bearing against the upper face of the idler mounting 55 and the head of the pin 83 is secured against the other face of the idler mount 55, thus supporting and positioning the pin 8|. 7

The bearing sleeve 80 carries fixedly secured thereto and therefore rotatable therewith at the upper end thereof an arm 90, the arm having a perforation which is mounted over the sleeve 80 and carrying a set screw 9| which is rotatable into engagement with the surface of the sleeve 80 in order to secure the arm thereto. The opposite end of the arm 90 has secured thereto a pin 92 the lower end of which is mounted in a suitable opening in said arm. The projecting end of the pin 92 has at 93 a bearing surface upon which the idler 50 carrying the tire 52 is rotatably mounted. 1

The lower end of the sleeve 80 is connected to or integrally extended into a shift lever I00. Movement of the shift leverto the various positions shown, for instance, by the drawings of Figures 2, 3 and 4 will cause the sleeve 80 to rotate. Rotation of the sleeve 80 will result in a corresponding rotation of the arm 90 and a corresponding rotation therefore of the pin 92 and its extension 93 and will thus cause. the center of the idler 50 to swing about the center of the idler 5| so as to vary the positions of the idlers with respect to each other.

The speed adjustment herein provided for is one which depends upon the operation of the lever I and the movement thereof to three different positions for the purpose of effecting the speed changing operation herein described. Preferably, however, in the embodiment herein shown the two idlers are of the same diameter and a variation in the diameter of the motor spindle 44 is relied upon to obtain the change in speed.

Thus, as is seen in Figures 1 and 6, the spindle 44 has a slow speed portion or a restricted diameter portion |0| at its upper end and a higher speed portion or an enlarged diameter portion at its lower end |02.

The high speed portion I02 of the spindle 44 is engageable only with the high speed idler and the low speed or restricted diameter portion |0| oi the spindle 44 is engageable only with the low speed idler 50.

The idlers 505| are low speed and high speed respectively only because they are so positioned that they can engage only a particular portion of the spindle and, in this particular embodiment of the invention, it is only the difference in the diameter of the portion of the spindle which bears against the idlerwhich determines the particular speed variation required.

The purpose of the lever I00 is therefore to either swing the high speed idler 5| against the portion I02 of the spindle or to swing the low speed idler 50 against the portion |0| of the spindle, thereby pushing the high speed idler 5| away from the spindle, or to so position the idlers' at the same time is pressed against the flange 42". of the turntable and thus rotative motion from" the motor is communicated through the small diameter portion |0| of the spindle to the peripheral portion of the-idler 50 and therefrom to the downturned flange 42 which results in rotation of the turntable 40.

By reason of the engagement of the idler 50 against the restricted portion of the spindle |0|, the floating mounting 55 has been rotated sufficiently to move the idler 5| out of engagement with the portion I02 of the spindle; and thus even though'the idler 5| may be pressed against the flange 42, since it is not pressed against the spindle, I10 rotative power 18 connriunicated IIOIll the portion I02 of the spindle to the flange 42 of the turntable, and the only rotative power transmitted to the turntable is that through the restricted portion |0| of the spindle and. the idler 50.

When the lever I00 is moved from the position shown'in Figure 2 to the position shown in Fi ure 3, it results in a corresponding rotation of the sleeve and consequently of the arm and of the center or mounting 93 of the idler 50 about the center of the idler 5|.

By this operation the idler 50 is brought to bear against the restricted portion |0| of the spindle 44 at such a position that the idler 50 is no longer in engagement with the flange 42 of the turntable. The spring 60 has, however. forced the floating mounting plate 55 over to a position wherein the high speed idler 5| is one gaged against the enlarged diameter portion' N2' of the spindle and is simultaneously engaged against the flange 42 of the turntable and hence rotative motion is transmitted from the enlarged portion of the spindle to the turntable.

When the lever M0 is moved to the position shown in Figure 4, then again the sleeve 80 and its arm 90 is rotated, thus once more swinging the center 93 of the idler 50 about the center of the idler 5| and although the idler 50 is now pressed against the spindle 44, the center 93 of the idler 50 is sufficiently displaced with respect to the center of the idler 5| as to force the idler 5| away from the spindle. Thus in this case the idler 5| is pressed against the flange 42 of the turntable while the idler 50 is pressed against the spindle but neither of the idlers is in engagement with both the spindle and the turntable and hence no rotative power can be transmitted from the spindle to the turntable.

The various difierent positions above described will be obvious from an examination 01 the figures and. or the description in connection therewith. It is suflicient to say that in Figure 2 the idler 50 is in engagement between the spindle and the turntable and prevents the idler 5| from being in engagement therewith since the center of the idler 50 is closer to the spindle and hence the action of the spring 60 which tends to rotate the mounting plate '55 is inhibited when the idler 50 engages the'spindle and thus the idler 5| cannot be forced against the spindle.

In Figure 3 the center of the idler 50 has been rotated to such a position that the distance between the center of the idler 5| and its portion I02 of the spindle is less than the distancebetween-the center of the idler 50 and its portion of the spindle and hence the idler 5| is permitted I to come into engagement with'the spindle by the action of the spring and into simultaneous engagement with the flange 42 for the transmission of rotative power.

In the position of Figure 4, the centers of. the two idlers are so lined up that the center of the idler is'closer to the flange 42 of the turntable and the center of the idler 50 is closer to the spindle, thus preventing complete contact by idler '50 and for stop position the center of idler 50 is closer to the spindle, and the center of the idler 5| is closer to the flange, thus preventing complete contact by both idlers.

Thus by the movement of the lever and the consequent rotation of the sleeve 80 about the pin 8|, it is possible to change from low speed to highspeed and vice versa, and, to stop the turntable by the means herein described for the purposes hereina'bove mentioned. A stopping of the turntable occurs only by reason of the disengagement of the idlers from between the motor spindle and the turntable and hence it is not necessary to halt the motor or other operating members in order to stop the rotation of the turntable.

Likewise it is possible to change from low speed to high speed and back once more without halting the operation of the motor and other operative connections.

The link action when the offset arm 90 is revolved' around the post 8|, workingon a toggle principle, produces a sufllcient action to lock the members in the desired position for "fast" or slow operation.

Other means may be provided inconnection with the lever I00 for releasably locking the-lever I00, in the position in which it is left. Such means will now be obvious to those skilled in the art.

The mounting plate 20 may carry any suitable legends which are necessary to indicate what a particular position of the lever I00 may mean. Thus, for instance, the legends Slow, Stop, and Fast" may be placed upon the mounting plate as shown in the figures or the legend Cut may be substituted for the legend Fast and the legend Play may be substituted for the legend Slow or any other suitablelegen'ds may be utilized.

Utilizing the same principles, that is, the principle of the rotation of the center of the low speed idler 50 about the center of. the high speed idler 5| inorder to obtain the various changes in speed, modifications may be made in the manner of obtaining this result.

Thus in cases where the base 20 is depressed so that the turntable rides almost flush with the surface of the plate and the flange of the turntable enters into the depression, the lever may be modified in order to obtain proper operation thereof. I

Thus as shown in Figures 7 and 9, the baseplate 20 has been depressed at I20 so that the surface of the turntable 40 rides almost flush with the base plate 20 and so that the flange 42 of the turntable rides virtually within the depression.

The mounting plate 55 is constructed and mounted in the same manner and carries the same members as has heretofore been described in connection with Figures 1 to 6 inclusive.

The lever I00, however, is led out through an opening I2I in the wall I22 of the depression I20. This opening is of sufllcient width to, permit the lever I00 to be moved to each of the three positions as indicated by the dotted lines of Figure '7. The positions of the lever I00 for Fast, Slow, and Stop in Figure 7 are the same as the positions of the lever I00 for the same operations in Figures 1 to 6 inclusive.

The end of the lever I00 is engaged in an opening I24 in a link I25. The link I25 extends around the outside of the wall I22 of. the depression and, if desired, may be guided by the additional track member I26 which is secured beneath the depression I20.

The link I25 has at the opposite end thereof from the endat which it engages the lever I00 an indicating portion I21 which extends up through a slot I28 in the base plate 20 of the recording apparatus.

The indicating portion I21 which extends through the slot I28 may be, if desired, bent over at I29 and shaped or formed in any suitable manner to provide a means for grasping the said indicating portion and moving the same as well as a means for indicating the setting of the lever I00.

When the portion I29 is set as shown in Figure 7, then the lever I00 is likewise set as is shown in Figure 7 and in accordance with the foregoing explanations with respect to Figures 1 to 6, it will now be obvious that the mechanism is set for operation at the slow speed.

When the indicating portion I29 is moved to the Fast setting, then the lever I00 is moved to the position shown by the dotted lines and in accordance with the previous description, it will now be obvious that the apparatus is set for the fast operation.

The movement of the outside indication portion I29 t0 the Stop" position will cause the lever to move to a position intermediate between the Slow and Fast settings and again in accordance with the principles outlined in connection with Figures 1 to 6, the operative connection between the turntable and the motor drive will be the idler 5|. Again the same type of mechanism is mounted upon the floating mounting plate including the mounting of one of the idlers 50 so that its center is rotatable about the center of the idler 5I and the mounting of the idler 5| so that it rotates about pin Ill and sleeve 80. Instead, however, of using a lever I or a lever I00 to effect the adjustment, the base of the sleeve 00 is widened and is extended into the form of the gear segment I50 as shown in Figures 8 and 10.

The rotation of the gear segment I50 to each of the three different positions hereinbefore described will produce the three different operations of Fast, Slow and Stop hereinbefore described and for this purpose another gear segment I i is utilized in order to rotate the gear segment I50.

The other gear segment I5I is fixedly attached to a pin I52 which is journalled in a sleeve I53. The opposite end of the pin I52 is fixedly secured to a handle and indicator I54. Rotation of the handle and indicator I 54 will result in corresponding rotation of the gear segment I5I, and the meshing of the gear segment I5I with the gear segment I5 will serve to transmit rotative power to the gear segment I50 and hence to rotate the sleeve 80 in the manner hereinbefore described and for the purposes hereinbefore described.-

In the embodiment shown in Figures 8 and 10, the turntable 40 is again shown mounted in a depression I20 although, of course, the same type of operation may occur whether or not the turntable happens to be mounted in a depression. When the handle I54 is rotated to the Slow setting as shown in Figure 8, the gear segment I5I is rotated thereby and hence rotates the gear segment I50 in a clockwise direction, thus rotate ing the sleeve 80 in the manner hereinbefore described in connection with the other modifications and hence bringing the idler 50 into engagement with both the spindle of the motor and the flange of the turntable.

Here 'it will be noted that the gear segment I50 has been moved in the same manner as have the lever I00 of Figure 2 or the lever I00 of Figure 7;

but that the handle I54 has been moved in theopposite direction to achieve this. result owing to the reversal of the motion occasioned by the interposition of a gear.

When the handle and indicator I54 is rotated to the Fast position, the gear segment I 5I is correspondingly rotated in a clockwise direction and the gear segment I50 is rotated in a counterclockwise direction in order to obtain the fast setting, the remaining members again being moved in the same manner as were the members of Figures 1 to 7.

Likewise when the handle I54 is moved to the Stop" indication, the motion is transmitted to the gear segment I5I and therefrom to the gear segment I50 through which it is transmitted to the sleeve 80 and thence to the arm 90 and thence to the center of the idler 50 in order to produce again the position of the idlers shown in Figure 4.

In the foregoing description I have described not merely the essential invention which comprises utilization of two idlers, each engageable with a different diameter of the spindle and the rotation of one idler about the center of the other in order to move a selected idler into or out of engagement with both the spindle and the turntable, but I have also described various means for obtaining this result and various practical commercial modifications of the primary idea. Many other uses and adaptations of the,device herein described will now be obvious to those skilled in the art and hence I prefer to be bound not by the specific disclosures herein but only by the appended claims.

I claim:

1. A speed changing drive for a turntable having a peripheral flange, said drive comprising a source of motive power, a spindle driven thereby, a pair of friction wheels and a floating mounting therefor, said mounting being yieldingly biased toward the spindle, one of said friction wheels being rotatable about a fixed support on said mounting, the other of said friction wheels being rotatable about a pin mounted eccentrically of the first of said friction wheels, said pin being movable about the said center of said first friction wheel to vary the distance of said pin from the spindle.

2. A speed changing drive 'for a turntable having a'peripheral flange, said drive comprising a source of motive power, a spindle driventhereby, a pair of friction wheels and a floating mounting therefor, said mounting being yieldingly biased toward the spindle, one of said friction wheels being rotatable about a bearing, said bearing being rotatable about a fixed support on said mounting, an arm secured to said bearing, the second of said friction wheels being rotatably mounted on said arm in a plane parallel to and abovethe first friction wheel, said second friction wheel being eccentric with respect to said first friction wheel and means for rotating said bearing to swing the center of said second friction wheel about-the center of said first friction wheel..

3. A speed changing drive for a turntable having a peripheral flange, said drive comprising a source of motive power, a spindle driven thereby, a pair of friction wheels and a floating mounting therefor, said mounting being yieldingly biased toward the spindle, one of said friction wheels being rotatable about a bearing, said bearing being rotatable about a fixed support on said mounting, an arm secured to said bearing, the second of said friction wheels being rotatably mounted on said arm in a plane parallel to and above the first friction wheel, said second friction wheel being eccentric with respect to said first friction wheel and means for rotating said bearing to swing the center of said second friction wheel about the center of said first friction wheel, said second friction wheel constituting the driving connection between the, spindle and flange when its center isnearer both the,

spindle and flange when its center is nearer both the spindle and the flange than the center of the second friction wheel.

4. A speed changing drive for a turntable having a peripheral flange, said drive comprising a source of motive power, a spindle driven thereby, a pair of friction wheels and a floating mounting therefor, said mounting being yieldingly biased toward the spindle, one of said friction wheels being rotatable about a hearing, said bearing being rotatable about a fixed support on said mounting, an arm secured to said bearing, the second of said friction wheels being rotatably mounted on said arm in a plane parallel to and above the first friction wheel, said second friction wheel being eccentric with respect to said first friction wheel and means by, a pair of the center of the second friction wheel, and

there being no driving connection between the spindle and the flange when the ,center of the second friction wheel is nearer the spindle than the center of the first friction wheel and when the center of the first friction wheel is nearer the flange than the center of the second friction wheel.

5. A speed changing drive for a turntable having a peripheral'flange, said drive comprising a source of motive power, a spindle driven therefriction wheels and a floating mounting therefor, said mounting being yieldingly biased toward the spindle, one of said friction wheels being rotatable about a bearing,

said bearing being rotatable about a fixed support on said mounting, an arm secured to said bearing, the second of said friction wheels being rotatably mounted on said arm in a plane parallel to and above the first friction wheel,

' said second friction wheel being eccentric with respect to said first friction wheel and means for rotating said bearing to swing the center of said second friction wheel about the center of said first friction wheel, said means comprising an arm secured to said bearing and extending beyond the periphery of the turntable.

6. A speed changing drive for a turntable having a peripheral flange, said drive comprising a source of motive power, a spindle driven thereby, a, pair of friction wheels and a floating mounting therefor, said mounting being yieldingly biased toward the spindle, one of said friction'wheels being rotatable about a bearing, said bearing being rotatable about a fixed support on said mounting, an arm secured to said bearing, the second of said friction wheels being rotatably mounted on'said arm in a plane parallel to and above the first friction wheel, said second friction wheel being eccentric with respect to said first friction wheel and means for rotating said bearing to swing the center of said second friction wheel about the center of said first friction wheel, said means comprising an arm secured to said bearing and extending beyond the periphery of the turntable, a link operatively connected to said arm and a handle and indicator secured to said link.

7. A speed changing drive for a turntable having a peripheral flange, said drive comprising a source of motive power, a spindle driven thereby, a pair of friction wheels and a floating mounting therefor, said mounting being yieldingly biased toward the spindle, one of said friction wheels being rotatable about a bearing, said bearing being rotatable about a fixed support on said mounting, an arm secured to said bearing, the second of said friction wheels being rotatably mounted on said arm in a plane parallel to and above the first friction wheel, said second friction wheel being eccentric with respect to said first friction wheel and means for rotating said bearing to swing the center of said second friction wheel about the center of said first friction wheel, said means comprising a gear segment, secured to said bearing, a second rotatable gear segment engageable with said first gear'segment, and a handle and indicator se-, cured to said second gear segment for rotating the same.

8. A speed changing drive for a turntable hav- 7 :ing a peripheral flange, said drive comprising a source of motive power, a spindle driven thereby, a pair of friction wheels and a floating mounting therefor, said mounting being yieldingly biased toward the spindle, one of said friction wheels being rotatable about a bearing, said bearing being rotatable about a fixed. support on said mounting, an arm secured to said bearing, the second of said friction wheels being rotatably mounted on said arm in a plane parallel to and above the first friction wheel, said second frictionwheel being eccentric with respect to said first friction wheel and means for rotating said bearing to swing the center of said second friction wheel about the center of said first friction wheel, said second friction wheel constituting the driving connection between the spindle and flange when its center is nearer both the spindle and the flange than the center of the first friction wheel; and said first friction wheel constituting the driving connection between the spindle and flange when its center is nearer both the spindle and the flange than the center of the second friction wheel, and there being no driving connection between the spindle and the flange, when the center of the second friction wheel is nearer the spindle than the center of the first friction wheel and when the center of the first friction wheel is nearer the flange than the center of the second friction wheel, said mounting being automatically adjustably positioned with respect to each position of the friction wheels.

9. A speed changing drive for a turntable having a peripheral flange, said drive comprising a source of motive power, a spindle driven thereby, apair of friction wheels and a floating mounting therefor, said mounting being yieldingly biased toward the spindle, one of said friction wheels being rotatable about a bearing, said bearing being rotatable about a fixed support on said mounting, an arm secured to said bearing, the second of said friction wheels being rotatably mounted on said arm in a plane parallel to and above the first friction wheel, said second friction wheel being eccentric with respect to said first friction wheel and means for rotating said bearing to swing the center of said second friction wheel about the center of said first friction wheel, said second friction wheel constituting the driving connection between the spindle and flange when its center is nearer both the spindle and the flange than the center of the ,flrst friction wheel; and said first friction wheel constitutlng the driving connection between the'spindle and the flange when its center is nearer both the spindle and the flange than the center of the second friction wheel, said spindle being of restricted diameter at the upper portion thereof at the area of engagement with the second friction wheel and being of larg- I PAUL STEAD GAY.

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