US3847027A

US3847027A - Speed control mechanism

Info

Publication number: US3847027A
Application number: US00302646A
Authority: US
Inventors: D Bailey
Original assignee: General Electric Co
Current assignee: RCA Licensing Corp
Priority date: 1972-11-01
Filing date: 1972-11-01
Publication date: 1974-11-12
Anticipated expiration: 1991-11-12
Also published as: DE2354177A1; GB1394844A; FR2204847A1; BR7308476D0

Abstract

A speed control mechanism provides a driving connection between a turntable and drive shaft of a record player. An idler wheel mounted on the mechanism engages different driving radii on the driving shaft to vary the rotational speed transmitted to the turntable by the idler wheel. The speed control mechanism resembles a crank and connecting arm with the idler wheel carried on the free end of the connecting arm. Upon rotation, the crank coacts with a camming means so that the crank, connecting arm and idler wheel are translated along the crank''s axis of rotation. The cranking effect and axial translation thereby serve to selectively position the idler wheel.

Description

United States Patent 11 1 1111 3,847,027

Bailey Nov. 12, 1974 SPEED CONTROL MECHANISM Primary Examiner--Samuel Scott Assistant E.\'aminer-Allan Russell Burke 75 I D B W b d V 1 mentor and C alley 00d n g6 a Attorney, Agent, or F1rmMarv1n Snyder [73] Assignee: General Electric Company,

Syracuse, NY. [57] ABSTRACT 22 N0 1 1972 A speed control mechanism provides a driving connection between a turntable and drive shaft of a re- [211 APPL 302,646 cord player. An idler wheel mounted on the mechanism engages different driving radii on the driving [52 US. Cl 74/190, 74/200, 74/206 shaft to y the rotational Speed transmitted to the 51 Int. Cl. Fl6h 15/08, Fl6h 15/46 turntable y the idler wheel- The Speed Control meeh- 53 Field f Search U 74 2 90 20 274 9 A anism resembles a crank and connecting arm with the idler wheel carried on the free end of the connecting 5 References Cited arm. Upon rotation, the crank coacts with a camming UNITED STATES PATENTS means so that the crank, connecting arm and idler 2 9 wheel are translated along the cranks axis of rotation. 2,925,737 2/l960 Hartman 74/l90 Th cranking effect and axial translation thereby Serve 1,386 9/1960 Edema 74/200 1 l h h l 2,961,883 11 1960 Hartman 1. 74 200 to se y Posmont er w 21 Claims, 5 Drawing Figures PAIENTEMunz m4 027 SHEET 2 OF 2 SPEED CONTROL MECHANISM INTRODUCTION The present invention relates to a new and improved speed control mechanism, and more particularly relates to a speed control mechanism which may be utilized in a record player or any variable or multiple speed drive train.

In prior art designs of speed control assemblies for record players, different mechanical arrangements have been provided for positioning an idler wheel between a driving shaft and a turntable on a record player. Such an idler wheel is usually made of rubber where it contacts the driving shaft and turntable, and the cooperating driving shaft includes stepped axial portions of necessarily different respective radii. As the idler wheel engages the different radii of the stepped axial portions, different rotational speeds are transmitted to the turntable as the driving shaft is maintained at a constant speed.

Heretofore, speed control assemblies for record players have been quite complex, requiring excessive time for assembly. Moreover, their complexity has tended to limit their reliability. Specifically, prior art designs have incorporated multiple camming surfaces with necessarily multiple, coacting parts in order to permit selective positioning of an idler wheel on a stepped driving shaft. The positioning of the idler wheel is accomplished through the resultant of its translation axially along the driving shaft to' different stepped portions thereof and its translation toward the driving shaft for engagement therewith.

The present invention is of less complexity than the prior art since it includes a structure having a minimum number of operational elements. This makes it relatively simple to assemble. The idler wheel is positioned by merely applying rotational force to a rotatably mounted member included in the structure of the invention. Only one cam and coacting camming surface are utilized. The invention provides speed control for a record player and may be adapted to other speed control applications.

Accordingly, it is an object of the present invention to provide an improved speed control mechanism for selectively positioning an idler wheel between a stepped driving shaft and a record player turntable to obtain desired rotational turntable speed.

A further object of the present invention is to reduce the number of elements required for a speed control mechanism for selectively positioning an idler wheel between a stepped driving shaft and a record player turntable.

Another object of the present invention is to provide a speed control mechanism which requires minimal assembly time.

In carrying out the objects of the invention, in one form thereof, a structure is provided for selectively positioning an idler wheel on different axial portions of a stepped driving shaft. The structure includes a J-shaped member rotatably mounted on a post which, in turn, is affixed to a base plate of a record player structure. A connecting member is rotatably coupled to the J- shaped member at a location radially removed from the stantially perpendicular thereto, at a point radially removed from the coupling between the J-shaped member and connecting member. The idler wheel can therefore be reciprocally translated in a plane perpendicular to the axis of the post as the two members (or more graphically the cranking arrangement which the two members collectively resemble) move through dead center with respect to each other.

The J-shaped member, which is also free to slide axially on the post, includes a camming surface that interacts with a camming means. Upon rotation of the J- shaped member, the camming means slideably urges the .I-shaped member axially along the post. The connecting member and the idler wheel necessarily are urged along the post together with the J-shaped member in a direction determined by the direction of rotation of the J-shaped member. Thus when the axial translation of the idler wheel along the post is vectorially added to its reciprocal translation in a plane perpendicular to the post, the resultant translation positions the idler wheel in engagement with a selected axial portion of a radially stepped driving shaft oriented parallel to the posts BRIEF DESCRIPTION OF THE DRAWINGS The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims set forth at the end of the specification. The invention, however, both as to organization and method of practice, may be best understood by reference to the following description, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a bottom view of the speed control mechanism as it is mounted on the base plate of a record player, with the base plate shown partially broken away for ease in understanding the invention;

FIG. 2 is another bottom view of the speed control mechanism showing the .l-shaped and connecting members at dead center position with respect to each other, with the base plate shown partially broken away;

FIG. 3 is a further bottom view of the speed control mechanism showing the idler wheel in engagement with the larger radius of the driving shaft after the J-shaped and connecting members have passed through the dead center position of FIG. 2, with the base plate shown partially broken away;

FIG. 4 is a side view of the speed control mechanism shown in FIG. 1, as viewed in the direction of arrow A; and

FIG. 5 is a side view of an alternative version of the speed control mechanism of the invention.

DESCRIPTION OF TYPICAL EMBODIMENTS As shown in FIG. 1 of the drawings, a base plate 2 which may be affixed to the underside of the housing (not shown) beneath a record player turntable 5, has a stationary post 4 rigidly mounted thereon so as to extend substantially perpendicularly downward from the plane of base 2. Although this embodiment of the invention is described with reference to a-record player structure, those skilled in the art will appreciate that base plate 2, mounting post 4 and associated elements to be described could be located or provided in various mechanical assemblies other than record player structures.

A member 6, conveniently J-shaped, is rotatably mounted on ,post 4 by passing the post through two aligned apertures formed in the parallel portions of the .l-shaped member referred to as first and

second mounting legs

8 and 10 respectively, leg 8 being the shorter of the two. The corresponding ends of

mounting legs

8 and 10 in FIG. 1 are connected by a camming surface 12 which forms the base of the J-shape. An actuating rod 19, through which manual force is transmitted by the turntable operator to change turntable speed, passes through an aperture 9 in leg 8. A substantially planar connecting member 14 is pivoted about leg 10 of J-shaped member 6 :at a point 16 radially removed from mounting post 4. A cutout 18in connecting member 14 permits the connecting member to rotate in a single plane about pivot point 16 due to the clearance for post 4 provided by cutout 18. It should be noted that rotatably mounted J-shaped member 6 and connecting member 14 respectively resemble a crank and a connecting arm.

An idler wheel 20 having a periphery comprised of a resilient material exhibiting a high coefficient of friction, such as rubber, is rotatably mounted on connecting member 14 at a point 22 radially removed from pivot point 16. The idler wheel has an elongated hub portion 23, as shown in FIG. 4, so as to allow the wheel to be situated above base plate 2 and permit it to contact the skirt 34 of turntable 36, as shown in FIG. 1.

When viewing FIGS. 1 and 2 in sequence, idler wheel 20 can be seen to translate toward post 4 as J-shaped member 6 is pulled by rod 19 so as to be rotated in a clockwise direction. As .I-shaped and connecting

members

6 and 14, respectively, pass through a dead center position with respect to each other, as illustrated in FIG. 2, the idler wheel is positioned to be reciprocally translated away from mounting post 4 as J-shaped member 6 continues to rotate clockwise, as shown in FIG. 3. A similar reciprocal translation of the idler wheel in a plane perpendicular to the axis of post 4, but in reverse sequence, will take place upon a corresponding counterclockwise rotation of J-shaped member 6 being pushed by rod 19.

As shown in FIGS. 1 and 4, stationary means in the form of a camming post 24 is rigidly affixed to post 4 and is disposed substantially perpendicular thereto. As further illustrated in FIG. 4, camming post 24 engages J-shaped member 6 by extending through a shaped slot 26 in camming surface 12. Slot 26 is closed at both ends, with each end oriented substantially perpendicular to post 4 and the center region being disposed at an oblique angle with respect to post 4. Since .l-shaped member 6 is free to slide axially on post 4, J-shaped member 6, connecting member 14 and idler wheel 20 are all displaced upward with respect to base plate 2, as shown in FIG. 4, when .I-shaped member 6 is rotated counterclockwise, as viewed from the free end of post 4. Similarly,

members

6 and 14 and idler wheel 20 are all displaced downward with respect to plate .2 when J-shaped member 6 is rotated clockwise, as viewed from the free end of post 4 as shown in FIG. 4. Accordingly, the location of idler wheel 20 along the longitudinal axis of post 4 is a function of the angular position of member 6 and is effected by the action of camming post 24 upon slot 26.

When the translation of idler wheel 20 toward and away from post 4, as described sequentially in conjunction with FIGS. 1, 2 and 3,is vectorially added to the translation along the axis of post 4, as described in conjunction with FIG. 4, it can be seen that idler wheel 20 is subjected to a resultant translation determined by the individual translations within a plane parallel to base plate 2 and along an axis normal to that plane.

A driving shaft 28 including two

stepped portions

30 and 32 of different size radii, as indicated in FIGS. 1 4, is disposed substantially parallel to post 4 atop the underside of the housing (not shown) beneath the record player turntable. In FIGS. 1 3, shaft 28 is viewable through the broken away portion of base plate 2. The idler wheel 20 is normally biased into engagement with one or the other stepped portions of driving shaft 28. As shown in FIG. 1, a tension spring 29 is used to hold idler wheel 20 in frictional engagement with the smaller radius of portion 30. FIG. 2 shows that as .lshaped member 6 rotates in a clockwise direction, idler wheel 20 moves from left to right, against the action of spring 29, and hence out of engagement with portion 30 of the driving shaft and, at the same time, upward out of engagement with turntable skirt 34. This is the neutral position of the mechanism in that idler wheel 20 is in full disengagement with both the motor and turntable. Additionally, the idler wheel is translated axially so as to be approximately at the step between

portions

30 and 32 on driving shaft 28.

The neutral position is an unstable one in that spring 29 urges idler wheel 20 toward driving shaft 28 whenever member 6 is but slightly displaced from dead center with respect to connecting member 14. In the alternative, a simple detent, such as shown in FIG. 5, may be employed to retain the mechanism in the neutral position. In such embodiment, spring 29 is incapable of moving the mechanism out of the neutral position, and a manual force must be applied to rod 19 in order to move the mechanism out of the neutral position.

As J-shaped member 6 is rotated further in a clockwise direction and out of the neutral position, idler wheel 20 is further translated axially with respect to driving shaft 28 so as to be positioned in alignment with portion 32 of the driving shaft. Therefore, as member 6 rotates further clockwise beyond dead center with respect to connecting member 14, as indicated in FIG. 3, idler wheel 20 moves from right to left, along with the action of spring 29, and hence is again located so as to engage driving shaft 28 and, at the same time, turntable skirt 34. However, due to the axial displacement of idler wheel 20, the larger radius of portion 32 is frictionally engaged by the wheel, the wheel being held in engagement therewith by tension spring 29.

The different radii of the stepped portions of driving shaft 28 in engagement with idler wheel 20 directly vary the speed of the idler wheel when driving shaft 28 rotates at constant speed. As is conventional in the art, the idler wheel is in frictional engagement with the turntable, at least concurrently with the time it is in frictional engagement with the driving shaft, so as to impart an angular velocity to the turntable which is proportional to the angular velocity of the idler wheel. Consequently only a rotational force need be imparted to .I-shaped member 6 in order to effect a speed change or, more specifically, a change of engagement location of idler wheel 20 along driving shaft 28.

FIG. 5 illustrates an alternative embodiment of the invention, wherein like numerals indicate like portions shown in FIGS. 1 4. In this embodiment, a detent is fabricated by

dimples

40 and 42 formed in connecting member 14 and in leg 10 of J-shaped member 6, re-

spectively. Member 14 and leg are shown partially cut away in order to better illustrate

dimples

40 and 42. The dimples are positioned to mate when the mechanism of the invention is in the neutral position, as shown in FIG. 2, and the mechanism illustrated in FIG. 5 is likewise in the neutral position. Thus, when the mechanism is in the neutral position, rod 19 must be pushed or pulled manually in order to move the mechanism into engagement with one or the other of stepped

portions

30 and 32 on the driving shaft.

While only certain preferred features of the invention have been shown by way of illustration, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

1 claim:

1. A speed control mechanism comprising:

a base plate;

stationary mounting post means rigidly affixed to said base plate;

a rotatable member mounted on said mounting post means so as to be rotatable thereabout, said member being slideable along the longitudinal axis of said mounting post means, said mounting post means including means engaging said rotatable member so as to urge said rotatable member along the longitudinal axis of said mounting post means in response to rotational movement of said rotatable member and in a direction determined by the direction of rotation of said rotatable member;

a connecting member pivoted about said rotatable member at a location radially removed from said mounting post;

a driving shaft including a plurality of driving radii;

and

a wheel rotatably mounted on said connecting member with its axis substantially perpendicular thereto, said driving shaft being engaged on a different one of said driving radii, respectively, by said wheel when said rotatable member is rotated from a first predetermined position to a second predetermined position.

2. The speed control mechanism of claim 1 wherein said rotatable member includes first and second mounting legs, each of said mounting legs being rotatably mounted on said mounting post means, and a camming surface joined to corresponding ends of said first and second mounting legs.

3. The speed control mechanism of claim 2 wherein said camming surface defines a slot in said rotatable member, and said mounting post means includes a camming post affixed thereto and extending through said slot to engage said camming surface.

4. The speed control mechanism of claim 3 wherein at least a portion of said slot is obliquely disposed with respect to the longitudinal axis of said mounting post means.

5. The speed control mechanism of claim 2 wherein said connecting member is pivoted about said rotatable member at a point on said second mounting leg.

6. The speed control mechanism of claim 5 wherein said second mounting leg is longer than said first mounting leg.

7. A speed control mechanism comprising:

a base plate;

a stationary mounting post rigidly affixed to said base plate;

a rotatable member mounted on said mounting post so as to be rotatable thereabout, said member being slideable along the longitudinal axis of said mounting post;

stationary means engaging said rotatable member so as to urge said rotatable member along the longitudinal axis of said mounting post in response to rotational movement of said rotatable member and in a direction determined by the direction of rotation of said rotatable member;

a driving shaft including a plurality of driving radii;

and

a wheel rotatably mounted on said connecting mem-.

ber with its axis substantially perpendicular thereto, said driving shaft being engaged on a different one of said driving radii, respectively, by said wheel when said rotatable member is rotated from a first predetermined position to a second predetermined position.

8. The speed control mechanism of claim 7 wherein said rotatable member includes a camming surface engaged by said stationary means.

9. The speed control mechanism of claim 8 wherein said rotatable member includes first and second mounting legs, each of said mounting legs being rotatably mounted on said mounting post, said camming surface being joined to corresponding ends of said first and second mounting legs.

10. The speed control mechanism of claim 8 wherein said camming surface defines a slot in said rotatable member, and said stationary means comprises a camming post affixed to said mounting post and extending through said slot to engage said camming surface.

11. The speed control mechanism of claim 9 wherein said camming surface defines a slot in said rotatable member, and said stationary means comprises a camming post affixed to said mounting post and extending through said slot to engage said camming surface.

12. The speed control mechanism of claim 10 wherein the longitudinal axis of said camming post is substantially perpendicular to the longitudinal axis of said mounting post and at least a portion of said slot is obliquely disposed with respect to the longitudinal axis of said mounting post.

13. The speed control mechanism of claim 11 wherein the longitudinal axis of said camming post is substantially perpendicular to the longitudinal axis of said mounting post and at least a portion of said slot is obliquely disposed with respect to the longitudinal axis of said mounting post.

14. The speed control mechanism of claim 9 wherein said connecting member is pivoted about said rotatable member at a point on said second mounting leg.

15. The speed control mechanism of claim 14 wherein said second mounting leg is longer than said first mounting leg.

16. A speed control mechanism comprising:

a base plate;

a stationary mounting post affixed to said base plate;

a rotatable member mounted on said mounting post so as to be rotatable thereabout, said member being slidable along the longitudinal axis of said mounting post;

a driving shaft including a plurality of driving radii;

a wheel rotatably mounted on said connecting member with its axis substantially perpendicular thereto, said driving shaft being engaged on a different one of said driving radii, respectively, by said wheel when said rotatable member is rotated from a first predetermined position to a second predetermined position; and

detent means for maintaining said rotatable member in engagement with said connecting member when said rotatable member is in a third position intermediate said first and second predetermined positions, said driving shaft being disengaged from said wheel when said rotatable member is in said third predetermined position.

17. The speed control mechanism of claim 16 wherein said detent means comprises a dimple in said rotatable member mated with a dimple in said connecting member when said rotatable member is in said third predetermined position.

18. Thespeed control mechanism of claim l4 including detent means for maintaining said second mounting leg in engagement with said connecting member when said rotatable member is in a third predetermined position intermediate said first and second predetermined positions, said driving shaft being disengaged from said wheel when said rotatable member is in said third predetermined position.

19. The speed control mechanism of vclaim 18 wherein said detent means comprises a dimple in said second mounting leg mated with a dimple in said connecting member when said rotatable member is in said third predetermined position.

20. The speed control mechanism of claim 16 wherein said rotatable member includes a camming surface engaged by said stationary means.

21. The speed control mechanism of claim 20 wherein said detent means comprises a dimple in said rotatable member mated with a dimple in said connecting member when said rotatable member is in said third predetermined position.

l =l =l=

Claims

1. A speed control mechanism comprising: a base plate; stationary mounting post means rigidly affixed to said base plate; a rotatable member mounted on said mounting post means so as to be rotatable thereabout, said member being slideable along the longitudinal axis of said mounting post means, said mounting post means including means Engaging said rotatable member so as to urge said rotatable member along the longitudinal axis of said mounting post means in response to rotational movement of said rotatable member and in a direction determined by the direction of rotation of said rotatable member; a connecting member pivoted about said rotatable member at a location radially removed from said mounting post; a driving shaft including a plurality of driving radii; and a wheel rotatably mounted on said connecting member with its axis substantially perpendicular thereto, said driving shaft being engaged on a different one of said driving radii, respectively, by said wheel when said rotatable member is rotated from a first predetermined position to a second predetermined position.

7. A speed control mechanism comprising: a base plate; a stationary mounting post rigidly affixed to said base plate; a rotatable member mounted on said mounting post so as to be rotatable thereabout, said member being slideable along the longitudinal axis of said mounting post; stationary means engaging said rotatable member so as to urge said rotatable member along the longitudinal axis of said mounting post in response to rotational movement of said rotatable member and in a direction determined by the direction of rotation of said rotatable member; a connecting member pivoted about said rotatable member at a location radially removed from said mounting post; a driving shaft including a plurality of driving radii; and a wheel rotatably mounted on said connecting member with its axis substantially perpendicular thereto, said driving shaft being engaged on a different one of said driving radii, respectively, by said wheel when said rotatable member is rotated from a first predetermined position to a second predetermined position.

16. A speed control mechanism comprising: a base plate; a stationary mounting post affixed to said base plate; a rotatable member mounted on said mounting post so as to be rotatable thereabout, said member being slidable along the longitudinal axis of said mounting post; stationary means engaging said rotatable member so as to urge said rotatable member along the longitudinal axis of said mounting post in response to rotational movement of said rotatable member and in a direction determined by the direction of rotation of said rotatable member; a connecting member pivoted about said rotatable member at a location radially removed from said mounting post; a driving shaft including a plurality of driving radii; a wheel rotatably mounted on said connecting member with its axis substantially perpendicular thereto, said driving shaft being engaged on a different one of said driving radii, respectively, by said wheel when said rotatable member is rotated from a first predetermined position to a second predetermined position; and detent means for maintaining said rotatable member in engagement with said connecting member when said rotatable member is in a third position intermediate said first and second predetermined positions, said driving shaft being disengaged from said wheel when said rotatable member is in said third predetermined position.

18. The speed control mechanism of claim 14 including detent means for maintaining said second mounting leg in engagement with said connecting member when said rotatable member is in a third predetermined position intermediate said first and second predetermined positions, said driving shaft being disengaged from said wheel when said rotatable member is in said third predetermined position.

19. The speed control mechanism of claim 18 wherein said detent means comprises a dimple in said second mounting leg mated with a dimple in said connecting member when said rotatable member is in said third predetermined position.