US2788669A

US2788669A - Plural speed phonograph mechanism

Info

Publication number: US2788669A
Application number: US506255A
Authority: US
Inventors: Roland H Richards
Original assignee: Alliance Manufacturing Co Inc
Current assignee: Philips Home Products Inc
Priority date: 1955-05-05
Filing date: 1955-05-05
Publication date: 1957-04-16
Anticipated expiration: 1974-04-16

Description

April 16, 1957 Filed May 5, 1955 R. HJRICHARDS PLURAL SPEED PHONOGRAPH MECHANISM 2 Sheets-Shae: l

INVENTOR.

ROLAND 'H. RICHARDS April 16, 1957 R. H. RICHARDS 2,788,669

PLURAL SPEED PHONOGRAPH MECHANISM Filed May 5, 1955 2 Sheets-Sheet 2 INVENTOR. ROLAND H. RICHARDS By 6/00 V M turned turntable rim and a drive shaft.

United States Patent PLURAL SPEED PHONOGRAPH MECHANISM Roland H. Richards, Alliance, Ohio, assignor, by mesne assignments, to The Alliance Manufacturing Company,

Division of Consolidated Electronics Industries Corporation, Alliance, Ohio, a corporation of Delaware Application May 5, 1955, Serial No. 506,255 9 Claims. (Cl. 74-199) The invention relates in general to plural speed phonograph drives and more particularly to means for obtaining a turntable speed by the interposition of an intermediate speed reducing agency between the driving means and the driven means of a phonograph mechanism by a transverse shifting movement.

With the advent of 16 R. P. M. phonograph records just around the corner, in addition to 78, 45 and 33 R. P. M. records which are on the market at the present time, it has become very desirable to obtain a drive mechanism which would drive a turntable at any of the above mentioned speeds.

At the present time, the most acceptable three-speed drive mechanism is the type where the three speeds are obtained by interposing an idler wheel between a down- The drive shaft is provided with three stepped portions of varying diameters. These diameters are of a calculated diameter to give the desired 78, 45, and 33 revolutions per minute to the turntable. The idler wheel is moved from one stepped portion to another by cam mechanisms which first move the idler wheel laterally away from the drive shaft, then vertically and then laterally into engagement with another stepped portion. It will be noted thus far from the discussion above that all of the different speeds have been obtained by engagement of the idler wheel with varying diameters on the drive shaft. Taking for example a two-pole motor which is driving a drive shaft, which may be either a separate shaft or an extension of the motor shaft, it will be apparent that there is a drastic reduction in the numerical value of the diameter of the stepped portion of the drive shaft required to produce a turntable speed of 78 R. P. M. and that re-required to produce a. turntable speed of 33 R. P. M. It is impracticable, if not impossible, to further reduce another portion of the drive shaft to obtain a turntable speed of 16 R. P. M. This would result in a stepped portion so small that effective and continuous driving contact with the idler wheel could not be had. It is therefore necessary to obtain an intermediate speed reducing agency which may be interposed between the driving means and the driven turntable.

In the manufacture of the turntable, it is necessary to draw the turntable rim so that the idler wheel may engage the downturned rim in all of its driving positions. If the turntable rim were drawn deeper to provide for the extra vertical travel necessary for an additional stepped portion, it would in all probability result in eccentricities which would not be acceptable to the phonograph industry.

A still further reason for not placing an extra stepped portion on the drive shaft is that the drive shaft will necessarily have to be made longer, thus multiplying any force on the point of attachment of the drive shaft and also multiplying any bending of the shaft thus causing magnification of any eccentricities at the place where the extra stepped portion is added.

An object of the invention is to provide a plural speed phonograph drive mechanism whereby at least one of the speeds is attained by a transverse shifting movement.

Another object of the invention is to provide a plural 2,788,669 Patented Apr. 16, 1957 speed phonograph drive mechanism whereby a turntable is driven at least for one speed from a drive shaft by means of an idler wheel interposed between the drive shaft and the turntable and which is driven at another speed by disposing an auxiliary drive train between the drive shaft and the idler wheel by means of a transverse shifting of the drive train.

Another object of the invention is to provide a plural speed drive mechanism having first and second engaging rotatable members which are movable from a first to a second position and when so moved one of the rotatable members engages a power shaft which is driving a phonograph turntable through a free floating idler wheel and another one of the rotatable members engages the idler wheel pushing it away from the power shaft thereby causing the turntable to be driven from the power shaft through the first and second rotatable members and the idler wheel rather than directly from the power shaft through the idler wheel.

Another object of the invention is to provide a plural speed phonograph drive for driving a turntable whereby the higher speeds are obtained by successive steps on a power shaft and the turntable, and the lowest speed is obtained by the interposition of a drive train between the power shaft and the idler wheel by means of a transverse shifting movement whereby the power shaft and the idler Wheel are disengaged and the turntable is driven by the power shaft through the drive train and the idler wheel.

Other objects and a fuller understanding of this invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawings, in which:

Figure l is a plan view of the invention showing the phonograph turntable driven directly from a drive shaft;

Figure 2 is a view of the invention substantially the same as Figure 1, except that the turntable is adapted to be driven through the intermediate speed reducing agency of this invention;

Figure 3 is an elevational view of the invention of Figure 2;

Figure 4 is a view taken generally along the line 4-4 of Figure 1; and

Figure 5 is an isometric view of the shifter plate shown in the embodiment of the invention in Figures 1, 2 and 3.

The plural speed phonograph drive mechanism of this invention is indicated generally by the reference numeral 10 and includes generally a frame or cabinet plate 11, a motive power source 12 which is illustrated in this embodiment as a two-pole electrical motor and a plural speed driving means indicated generally at 13. A turntable spindle 16 is journalled on the cabinet plate 11 and is adapted to serve as the axis of rotation of a phonograph turntable 17. The phonograph turntable has a downwardly turned rim 18 which is adapted to be engaged by an idler pulley 19. A drive shaft 22 is operably connected to and is adapted to be driven by the motive power source 12. In the accompanying drawings, the drive shaft 22 is shown as an extension of the main shaft of the electric motor; but it will be readily apparent that this drive shaft may be connected to and driven by the motive power source by many suitable means. The cabinet plate or frame 11 has a first and a second side illustrated by the reference numerals 24 and 25, respectively. The electric motor 12 is attached to the first side 24 of the cabinet plate 11 by means of

support members

27, 28 and 29 which extend from the laminated core of the electric motor and which extend through the cabinet plate and are attached thereto by suitable means, such as by the nuts 30. Rubber grommets 31 are interposed between the support membcrs and the cabinet plate 11 to avoid any undesirable transmission of vibration greases from the electric motor to the cabinet plate. This undesirable quality is frequently referred to in the phono graph industry as rumble. A shifter plate or movable carrier is pivotally connected to the second side of the cabinet plate 11 by means of .a pivot member 36. The shifter :plate, .is shown in combination with the operative elements of the phonograph drive mechanism in Figures 1 and 2 and is. shown separate and apart from these elements in Figure 5. Means 39 are provided for moving the shifter plate 35 about the pivot member 36 from a first station indicated by the reference numeral 37 to a second station indicated by the reference numeral 38. The means 39 include a shifter lever 40 pivotally connected to the cabinet plate 11 and having an end portion 43 residing within a pocket 45 in the shifter plate 35. The shifter plate is illustrated in Figure l as being at the first station or position 37 and in Figure 2 as being at the second station or position 38. Detent means are provided for making the first and second stations 37and 38 more readily apparent to the operator of the phonograph drive mechanism, and to maintain the shifter plate 35 in a distinct predetermined position. The detent means include a first and a second aperture in the shifter plate indicated by the

reference numerals

48 and 49, respectively, a detent ball 59 and a spring member 51. The drive shaft 22 is illustrated in the accompanying figures as having first, second and third diameter drive portions indicated by the reference numerals .54, and 56, respectively. The first diameter drive portion is in a first plane perpendicular to the axis of the drive shaft and is adapted to rotate with the drive shaft upon rotation of the drive shaft about its axis. The idler Wheel 1? is rotatably mounted upon a movable member or idler plate 58 and is in turn pivoted to an idler link 59, and hence is adapted for free floating movement within limits with respect to the turntable 17 and the drive shaft 22. A spring 60 is provided for constantly urging the idler wheel 19 toward a portion of the turntable 17 and also toward the rotatable drive shaft 22. As shown in Figure 1, when the shifter plate 35 is located at the first station 37, engagement of the idler wheel 19 and the first diameter drive portion 54 of the drive shaft 22 and also engagement of the idler wheel with a portion of the downturned rim of the turntable is effected. The above-described engagement while the shifter plate is located at the first station 37 causes the rotation of the drive shaft 22 to be transmitted directly through the idler wheel to the turntable whereby the turntable is driven in a first direction at a first rotational speed.

The Figure 4 best shows a first and a second

rotatable member

63 and 64, respectively, journalled on the shifter plate 35 and adapted for rotation about their respective axes, which axes are substantially parallel to the axis of the drive shaft 22. The first rotatable member has first and second pulley portions thereon which are indicated by the reference numerals .67 and 68 respectively. The second rotatable member 64 has first and second pulley portions indicated by the reference numerals 7t) and '71, respectively. The first pulley portion 67 of the first rotatable member 63 engages the first pulley portion 70 of the second rotatable member 64 and the second pulley portion 68 of the first rotatable member 63 is spaced from the second pulley portion 71 of the second rotatable m mber 64.-

The invention has been illustrated in conjunction with a vertical shifting type phonograph mechanism, such as more fully described in the copending application of Ernmor V. Schneider, Serial No. 166,035, filed June 3, 1950; and the remaining mechanical features will be described herein in order to give a thorough understanding of all of the mechanical features illustrated in the drawings.

A double-sided cam 73 is provided and is adapted for movement'with the shifter plate 35. In the embodiment of this invention, the double-sided cam 73'has been shown as an integral part of the shifter plate 35 by means of making the entire assembly out of one stamped piece. The double-sided cam '73 is provided with first, second and third vertically spaced horizontal steps '76, 77 and 78, respectively, interconnected by sloping cam surfaces 81 and 32. A cam follower bit is connected to the idler link 5% and hence transmits movement to thislink 53 and to the movable member 58 and idler wheel 19. The cam follower is adapted to oo-act with the first, secend and third steps and with the sloping cam surfaces of the cam 73 upon movement of the shifter level .49 and hence upon movement of the shifter plate 35. A second cam 74 is provided and is made in this embodiment as an integral part of the shifter plate 35. A second cam follower '75 is provided as an extension of the pivot pin 72 interconnecting the idler linl; 59 and the idler plate 53, and moves in response to the cam '74. The second cam and cam follower impart lateral movement of the idler wheel away from the drive shaft 22, with movement toward the drive shaft 22 effected by the idler spring ()6, The movement of the cam follower E9, in conjunction with the movement of the second cam follower 75, from one of the vertically spaced horizontal steps to another causes the idler wheel 19 to travel in a U-shaped path from one of the diameter drive portions on the drive shaft to another of the diameter drive portions on the drive shaft. This movement might be described as a movement away from one of the drive portions of the drive shaft, a vertical movement, and then a movement toward another of the diameter drive portions of the drive shaft.

As best seen in Figure 5, the first horizontal step '76 is of greater extent than the horizontal steps 77 and '78. This step '76 is extended so as to receive the can. follower it without producing a vertical movement of the idler wheel while the shifter plate travels between the first and

second positions

37 and 38, respectively. The shifter plate 35 is provided with a cut out area 33 which produces the second cam 7d and provides a regularly continuing surface 34 which is adjacent the second cam follower 75 upon movement of the shifter plate 35 between the first and

second stations

37 and 31$. This cut out area 83 provides room for lateral movement of the second cam follower '75 and hence the limited free floating movement of the idler wheel 1?. it will therefore be apparent that as the shifter plate 35 travels between the first and second stations 3'7 and 38, there is no movement, either lateral or vertical, imparted to the idler wheel by the first and second cams '73 and 74 respectively.

When the shifter plate 35 is located at the first station 37, the turntable i7 is driven by movement transmitted from the electric motor to the idler wheel 19 by the engagement of the idler wheel with the first diameter drive portion 54 of the drive shaft 22 and with the additional engagement of the idler wheel with the downturned rim 18 of the turntable 17. Movement of the shifter plate 35 to the second station 38 causes transverse shifting engagement of the second pulley portion 53 of the first rotatable member as with the first diameter drive portion 5 3 of the drive shaft 22 and also causes transverse shifting engagement of the second pulley portion 71 of the second rotatable member 64 Withthe idler wheel which thereby pushes the free floating idler wheel out of engagement with the first diameter drive portion 54 of the drive shaft 22 and the turntable is then driven or rotated through the intermediate speed reducing agency of the first and second rotatable members in the same rotational direction but at a second rotational speed which in this case would be 16 R. P. M.

It will thus be seen that with the particular mechanism which has been described in this invention, at'least four speeds may be attained from this drive mechanism without encountering additional manufacturing problems. It will be seen that turntable rims will not have to be drawn any deeper than they are at the present time and that the length of the drive shaft will not have to inade longer, thereby obviating the possibility of undue bending of the drive shaft by any forces which are applied to its outer extremities. It is also possible by means of this invention to obviate the necessity of adding a still further reduced diameter portion to the drive shaft which would give a very ineffectual frictional driving engagement with the idler wheel. It will also be apparent that while the shifter plate is in the first position 37, the first and second

rotatable members

63 and 64 are not being moved at all, therefore giving a prolonged life to these rotatable members.

It will be noted that the first and second

rotatable members

63 and 64 comprise very compact speed reducing agency for interposition between the driving means and the driven means. These rotatable members provide, by their physical construction and location, the most rugged type of speed reduction unit for engaging the idler wheel and the drive shaft with respect to bending of any of the members about their respective axes of rotation. Since these rotatable members are adapted to frictionally engage the motor shaft and the idler wheel, it is necessary that there be little, if any, bending of these members. If bending results continuous frictional engagement between the rotatable members, the drive shaft and the idler pulley cannot be had, and hence variations in the turntable speed will result. With the sturdy construction of the speed reducing agency of this invention, there is no need for concern about poor frictional engagement between any of the above-mentioned elements. The reduction of the turntable speed from 78 R. P. M. to 16 R. P. M. is much more easily stepped down by the use of the two rotatable members of this invention than any other mechanism, while still maintaining the abovementioned compactness and ruggedness of the unit. It will also be noted that with the use of the two rotatable members of this invention, the idler wheel, and hence the turntable, are driven in the same rotational direction when :the speed reducing agency is engaged as when they are driven directly from the motor shaft. From a view of .the drawings of this invention, it will also be apparent that there is no metal-to-metal contact of any of the rotating members. This fact along with the fact that rub- .ber grommets are used in sound insulating the driving .means from the cabinet plate, provides a most desirable unit with respect to the elimination of transmission of undesirable noise and vibration.

In reviewing the many advantages of this invention in comparison with providing a further stepped pulley on the drive shaft, it would be well to take, for example, an actual case and consider the various physical sizes of the diameter drive portions necessary to drive an eight inch turntable at 33 to 16 R. P. M. from a two pole motor. Assume that a two pole motor is driving the motor shaft at 3450 R. P. M., it is then necessary that the portion of the shaft engaging the idler wheel be approximately .074 of an inch in diameter in order to drive an eight inch diameter turntable at 33 R. P. M. It will be easily recognized that this is very small in physical size and thus much weaker than a larger portion. Now assume that we wish to drive the turntable at 16 R. P. M. in this same manner. It would then be necessary to add another stepped portion on the drive shaft Which would be further from the bearings supporting the shaft and which would have to be approximately .037 of an inch in diameter. It is therefore obvious that a very weakened portion would result and which would be located a large distance from the bearings supporting the shaft on which it would reside. This produces a long lever arm which tends to magnify any eccentricities on the reduced diameter portion; and since the eccentricities have to be kept down in the neighborhood of one-half of one thousandth of an inch for commercial acceptance, it can be seen that a reduced portion of this size would be highly undesirable. When the stepped drive diameter is reduced to the value of 037 of an inch in diameter, as pointed out above, continuous frictional driving contact of the required torque with the idler wheel is unpredictable if not impossible.

Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is:

1. In a sound reproducer drive mechanism for driving an output wheel including a rotatable drive shaft, a shifter plate pivotally connected to said mechanism for arcuate movement, a first and a second rotatable member journalled for rotation on said shifter plate on axes a fixed distance apart, first and second portions on said first rotatable member, said first portion of said first rotatable member engaging said second rotatable member, movement of said shifter plate causing said second portion of said first rotatable member to engage said drive shaft and causing said second rotatable member to engage a portion of the output wheel whereby said wheel. is driven by said drive shaft.

2. In a phonograph drive mechanism for driving a turntable including a drive motor, a drive shaft adapted to be driven by said drive motor, a cabinet plate, a shifter plate pivotally connected to said cabinet plate for arcuate movement thereabout, an idler wheel adapted to engage and drive the turntable, a first and a second rotatable member journalled for rotation on said shifter plate, each said first and said second rotatable member having a first and a second pulley portion thereon, said first pulley portion of said first rotatable member engaging said first pulley portion of said second rotatable member, movementof said shifter plate causing said second portion of said first rotatable member to engage said drive shaft and causing said second portion of said second rotatable member to engage a portion of the idler wheel whereby said turntable is driven by said drive motor.

3. In a plural speed phonograph drive mechanism for driving a turntable including a drive motor having a drive shaft extension extending therefrom, a cabinet plate having first and second sides, said drive motor connected to said first side of said cabinet plate with said drive shaft extension extending through said cabinet plate to said second side of said cabinet plate, a shifter plate, a pivot member, said pivot member pivotally connecting said shifter plate to said second side of said cabinet plate, an idler wheel mounted for free floating movement between said turntable and said drive shaft extension for transmitting movement from said drive shaft extension to said turntable, spring means urging said idler wheel toward said drive shaft extension and said turntable, a first and a second rotatable member journalled for rotation on said shifter plate, each said first and said second rotatable member having a first and a second pulley portion thereon, said first pulley portion of said first rotatable member engaging said first pulley portion of said second rotatable member, means for moving said shifter plate about said pivot member, engagement of said idler wheel with said drive shaft extension and said turntable causing said turntable to move at a first speed, movement of said shifter plate about said pivot member causing said second portion of said first rotatable member to engage the drive shaft extension and causing said second portion of said second rotatable member to engage a portion of said idler Wheel thereby moving said idler wheel away from said drive shaft extension while still maintaining said idler wheel in contact with said turntable whereby said turntable is driven at a second speed.

4. In a plural speed phonograph drive mechanism for 7 driving a turntable by frictional engagement of an idler wheel with the inner annular surface of a down-turned rim of the turntable, including a shaft adapted to be driven by a motive power source, a cabinet plate, a shifter plate pivotally connected to said cabinet plate for arcuate movement thereabout, a first and a second rotatable member mounted for rotation on said shifter plate on fixed spaced apart axes, means for moving said shifter plate from a first to a second station, location of the shifter plate at said first station effecting engagement of the idler wheel by said shaft thereby causing the turntable to to tate in a first direction at a first rotational speed, each said first and second rotatable member'having a first and a s on P ll y po tion, sa d firs pu y po -i o s first member at all times engaging said first pulley portion of said second member and said second pulley port-ion of said first member being spaced from said second pulley portion of said second member, movement of said shifter plate to said second station causing transverse shifting engagement of said second pulley portion of said second rotatable member with the idler wheel thereby pushing the idler wheel away from said shaft and causing trans verse shifting engagement of said second pulley portion of said first rotatable member with said shaft'whereby the turntable is rotated in said first direction at a second rotational speed.

5. Ina plural speed phonograph drive mechanism for driving a turntable including a drive motor, a drive shaft operably connected to and adapted to be driven by said drive motor, a cabinet plate having a first and a second side, said drive motor being attached to said first side of said cabinet plate, a shifter plate, a pivot member, said pivot member pivotally connecting said shifter plate to said second side of said cabinet plate, means for moving said shifter plate about said pivot member from a first to a second station, an idler wheel mounted for free floating movement with respect to said turntable and said drive shaft, means urging said idler wheel toward a portion of said turntable and also toward said rotatable shaft, location of said shifter plate at said first station causing engagement of said idler wheel with said drive shaft and said portion of said turntable and causing rotation of said turntable in a first direction at a first rotational speed, a first and a second rotatable member mounted on said shifter plate, each said first and said second rotatable member having a first and a second pulley portion thereon, said first pulley portion of said first rotatable member engaging said first pulley portion of said second rotatable member, said second pulley portion of said first rotatable member spaced from said second pulley portion of said second rotatable member, movement of said shifter plate to said second station causing transverse shifting engagement of said second pulley portion of said first rotatable member with said drive shaft and causing transverse shifting engagement of said second pulley portion of said second rotatable member with'the idler wheel thereby pushing said free floating idler wheel away from said drive shaft whereby said turntable is rotated in said first direction at a second rotational speed.

6. A phonograph drive for driving a phonograph turntable from a motor comprising, a frame, a drive shaft rotated about an axis from said motor and having a drive portion in a first plane perpendicular to said axis, an idler wheel adapted for driving engagement with a turntable and disposed on an axis parallel to said drive shaft axis and in substantially said first plane, a movable carrier on said frame, first and second rotatable members carried on said movable carrier for rotation on axes parallel to said drive shaft, each of said rotatable members having two stepped portions of different diameters with the large diameters of each thereof being provided with first and second rubber-like friction tires, respectively, the friction tire of the second rotatable member being in constant frictional peripheral engagement with the smaller stepped portion .of the first rotatable member, said frictional tire of the firstrotatable member being of a smaller diameter than the frictional tire of the second rotatable member so as to maintain said first friction tire out of'engagement with the smaller stepped portion of said second rotatable member, detent means establishing first and second positions of said movable carrier, said movable carrier in said second position effecting frictional peripheral engagement of said drive shaft and said first friction tire and concurrently effecting peripheral friction drive engagement between said idler wheel and the small steppedportion of said second rotatable member, and said first detent position effecting a lateral shifting of said movable carrier and con.- sequently a lateral shifting of said first and second rotatable members as a unit to separate said first friction tire from said drive shaft and to simultaneously sepa rate said small stepped portion of said second rotatable member from said idler wheel. a

7. In a phonograph drive mechanism for driving a turntable including a cabinet plate, a drive motor con.- nected to said cabinet plate, a drive shaft adapted to be driven by said drive motor, a shifter plate carried by and movable relative to said cabinet plate, an idler wheel carried for rotation as part of said mechanism and adapted to engage and drive the turntable, a first and a second rotatable member journalled for rotation on and adapted for movement with said shifter plate, first and second portions on said first member, said first portion of said first rotatable member being in driving engage ment with said second rotatable member, movement of said shifter plate relative to said cabinet plate causing said second portion of said first rotatable member to engage said drive shaft and causing said second rotatable member to engage a portion of said idler wheel whereby said turntable is driven by said drive motor.

8. =In a phonograph drive mechanism for driving a turntable including a drive motor, a drive shaft iad-aped to bedriven by said drive motor, a cabinet plate, a shifter plate carried by and movable relative to said cabinet plate, an idler wheel carried for rotation as part of said mechanism and adapted to engage and drive the turntable, a first and a second rotatable member journalled for rotation and adapted for movement with said shifter plate, each said first and said second rota-table member having a first and a second pulley portion thereon, said first pulley portion of said first rotatable member engaging said first pulley portion of said second rotatable member, movement of said shifter plate relative to said cabinet plate causing said second portion of said first rotatable member to engage said drive shaft and causing said second portion of said second rotatable member to engage a portion of the idler wheel whereby said turntable is driven by said drive motor.

9. In a phonograph mechanism for moving a table including a drive motor, a drive shaft mounted by said mechanism and driven by said drive motor, a plate mounted on said mechanism, an idler wheel adapted to engage and drive said table, a first and a second rotatable member journalled for rotation on said plate, each said first and said second rotatable member having a first and a second portion, said first portion of said first rotatable member engaging said first portion of said second rotatable member, movement of said plate and said mechanism relative to each other causing said second portion of said first rotatable member and said drive shaft to engage each other and causing said second portion of said second rotatable member and a portion of said idler Wheel to engage each other whereby said table is driven by said drive motor.

References Cited in the file of this patent UNITED STATES PATENTS