US3339928A

US3339928A - Velocity trip mechanism

Info

Publication number: US3339928A
Application number: US424897A
Authority: US
Inventors: Calvin G Wolthausen
Original assignee: Thomas International Corp
Current assignee: Thomas International Corp
Priority date: 1965-01-12
Filing date: 1965-01-12
Publication date: 1967-09-05
Anticipated expiration: 1984-09-05
Also published as: GB1116968A

Description

P 5, 1967 c. G. WOLTHAUSEN VELOCITY TRIP MECHANISM Filed Jan. 12, 1,965

1/32/2172 of w aadwz WW, @6471, {7759M United States Patent 3,339,928 VELOCITY TRIP MECHANISM Calvin G. Wolthausen, Palatine, Ill., assignor to Warwick Electronics Inc., a corporation of Delaware Filed Jan. 12, 1965, Ser. No. 424,897 Claims. (Cl. 274-1) ABSTRACT OF THE DISCLOSURE A trip mechanism for initiating a change cycle in a record changer including a cycle gear having first and second longitudinally movable links mounted directly thereon, with the first link being movable by means responsive to movement of a tone arm, and the second link engaging a trip pawl pivotally mounted on the cycle gear. The links are normally retained for movement together by clutch means, but the second link is capable of moving longitudinally relative to the first link when a cam surface on the pawl is engaged by an abutment carried by the record changer turntable.

This invention relates to record players, and more particularly to an automatic record changer for sequentially playing a plurality of records.

1 In the past it has been conventional to provide a record with a relatively widely spaced spiral lead out groove at the end of the recorded material, so that the tracking of the record changer tone arm across the record will be accelerated at the end of record play. This accelerated tone arm movement has been conventionally utilized to actuate a trip mechanism and initiate a record change cycle. Known types of trip mechanisms have possessed many serious defects, rendering them unreliable in operation and difiicult to service. Such trip mechanisms have usually included a relatively complex linkage system which has made the trip mechanism expensive to fabricate and assemble.

- Accordingly, the general purpose of the present invention is to provide a trip mechanism for an automatic record changer which is simple in construction, efi'icient in operation, and relatively inexpensive to manufacture and maintain.

- An object of the invention is to provide a velocity trip mechanism with a simplified linkage means wherein a pair of links for effecting a record change cycle are each mounted together on a record change cycle drive gear.

Another object of the invention is to provide a trip mechanism as described in the preceding paragraph wherein the links are nested together and stacked one upon the other.

A further object of the invention is to provide a trip mechanism as described above with novel means for resetting the linkage means.

Still another object of the invention is to provide a trip mechanism as described above with a single reset means for simultaneously moving each of the links, and a pawl that is actuated by one of the links from an operating position to a non-operating position after a record change cycle has been initiated.

These and other purposes of the invention will hereinafter become more fully apparent from the following description taken in connection with the annexed drawing, wherein:

FIG. 1 is a fragmentary plan view of a prefer-red record changer embodiment with certain parts being broken away for clarity of illustration;

FIG. 2 is an enlarged plan view of the trip mechanism showing the linkage means in non-operating position which it occupies during record play; and

3,339,928 Patented Sept. 5, 1967 FIG. 3 is a sectional view taken generally along line 3-3 of FIG. 2.

While this invention is susceptible of embodiment in many different forms, there is shown in the drawing and will herein be described in detail one specific embodiment, with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated. The scope of the invention will be pointed out in the appended claims.

The illustrated record changer embodiment includes a generally rectangular motorboard 10 having a central well 11, in which a turntable 12 is rotatably mounted. The upper surface of the turntable 12 is preferably provided with a cushioning mat, for engaging the under 1 surface of a record R supported thereon. As is well known in the art, turntable 12'includes a depending annular flange at the periphery thereof, which is adapted to be drivingly engaged by a motor driven wheel, not shown, for rotating the turntable.

The central portion of turntable 12 includes a central hole in which a hub 13 is held by a suitable fastener. A longitudinally extending radial lug or striker 14 is provided on one side of hub 13 for effecting the start of a record change cycle, as will hereinafter be more fully explained. A plurality of longitudinally extending teeth 15 are provided on the lower portion of hub 13 and define a pinion for driving a drive gear to be hereinafter explained.

The illustrated record changer embodiment includes a tone arm 16, which is provided with aconventional cartridge and stylus assembly at the outer end thereof for tracking the spiral groove of the record R. Tone arm 16 is mounted for pivotal movement about both a horizontal and a vertical axis by a suitable support 17 on motorboard 10. A pressure arm 18 is mounted on support 17 for pivotal movement as well as up and down movement with respect to motorboard 10. As is well known in the art, pressure arm 18 is adapted to overlie a stack of records to stabilize the same on a record changer spindle 19. As is conventional, an ejector lever is provided centrally of turntable 12 operatively associated with the spindle 19 and is adapted to eject the lowermost record in the record stack during a record change cycle.

A drive gear 20 is rotatably mounted beneath the motorboard 10, and includes a central hub 21 rotatably retained on a suitable pivot member on the motorboard. Gear 20 is'located adjacent hub 13, and the teeth on gear 20 are positioned for meshing engagement with the teeth 15 on hub 13. Gear 20 includes a portion 22 in which no teeth are provided, and as will hereinafter become more fully apparent, gear portion 22 is positioned adjacent hub 13 during the playing of a record, so that the gear 20 does not rotate. When the end of a record is reached, or when a reject cycle is initiated by manual actuation of a reject lever, not shown, a trip mechanism to be also hereafter described engages lug 14 on hub 13 to move the teeth on gear 20 into meshing engagement with teeth 15, whereby a record change cycle is effected.

The trip mechanism-includes a trip pawl or dog 23 which is pivotally mounted on the upper surface of gear 20 at 24. Pawl 23 includes an upstanding flange 25 at one side thereof defining a forward cam surface 25a, and a detent surface 26 disposed at substantially right angles thereto, for a purpose to be hereafter described. Pawl 23 is movable between an operating position wherein a portion of detent surface 26 is positioned outwardly of the outer periphery of gear 20, and a non-operating or record playing position wherein the entire detent surface 26 is positioned within the confines of gear 20. A slot 27 is provided in gear 20 to one side of hub 21 and in substantial alignment with gear portion 22. The trip mecha nisrn comprises linkage means including a lower actuating plate or link 28 slidably mounted on the gear 20, and having a tab 29 extending downwardly through slot 27 and an upwardly extending post 30. The linkage means further includes an upper plate or link 31 that is provided with a slot 32 which receives post 30 therethrough. A light spring 33 is biased between a suitable retaining member on post 30 and the upper surface of plate 31, to frictionally

clutch plates

28 and 31 for movement together.

The forward end of plate 31 includes a hook 34 which is attached to pawl 23 for movement thereof. To this end, pawl 23 is provided with an upstanding flange 35 spaced from and generally parallel with flange 25, and over which hook portion 34 is received. Thus, when upper plate 31 is moved to the left as view in the drawing, the rounded plate portion 31a opposite and facing hook 34 makes rolling and sliding contact with pawl 23 to cause the pawl to pivot in a counterclockwise direction about pivot 24 into position for engagement with lug 14 on hub 13.

Means are provided for guiding

plates

28 and 31 in their longitudinal movement, and include a headed member 36 suitably fixed on gear 20.

Plates

28 and 31 are provided with respective longitudinal notches 37 and 38 along one side thereof which engage hub 21 to guide

plates

28 and 31 and limit their movement. Additional longitudinal notches 39 and 40 are provided in the opposite sides of

plates

28 and 31, respectively, and engage the shank of member 36 to also guide the plates. The enlarged head of member 36 overlies upper plate 31, and cooperates with the retention member on post 30 to positively hold the plates on the gear 20.

The means for moving pawl actuating plate 31 to effect a record change cycle during the automatic playing of a stack of records includes a longitudinally extending link 41 which is mounted for longitudinal movement relative to the motorboard 10. Link 41 is operatively associated with tone arm 16, as by being connected to a cam 42 that is part of the record change mechanism and movable with the tone arm as it moves across the spiral groove of a record.

Thus, when the end of a record is reached, the movement of link 41 will be accelerated due to the engagement of the stylus carried by the tone arm with the more widely spaced spiral lead out groove at the end of a record. The left hand end of link 41, as viewed in the drawing, will then move into engagement with the downwardly extending tab 29 on lower actuating plate 28, and

plates

28 and 31 will be moved to the left because of the clutching action of spring 33. This movement will shift pawl 23 into position for engagement with lug 14. Additional movement of link 41 to the left as the stylus reaches the end of the record groove, will be taken up by the movement of the lower plate 28 relative to the upper plate 31 until the post 30 reaches the end of slot 32. Depending upon the amount of recorded material on the record being played, and the location of the records lead out groove, the end of the link 41 may engage tab 29 prior to the entry of the stylus into the lead out groove. In such a situation the plates 28 and 31 (and pawl 23) will be moved slowly toward the hub 13 as the record rotates. Eventually the leading surface 25a of pawl 23 may be moved into the path of travel of lug 14, and pawl 23 will be pivoted in a clockwise direction as viewed in FIG. 1 by frictional engagement of the lug 14 with the pawl to move plate 31 relative to plate 28. However, as the record continues to rotate and link 41 moves plate 28, plate 31 will move with plate 28 under the clutching action of spring 23 until pawl surface 25a again moves into engagement with lug 14. The sequence will be repeated until the record tracking stylus enters the record lead out groove whereupon the movement of link 41 will be accelerated, and the detent portion 26 of pawl 23 will be moved into position for engagement with lug 14 (FIG. 1) with an upstanding flange 23a on pawl 23 being positioned against member 36. The rotary movement of hub 13 will thereby be imported to gear 20 to bring the teeth thereon into mesh with teeth 15 to initiate a record change cycle.

An eccentric pin 45 extends downwardly from drive gear 20, and is adapted to drive a suitable record change mechanism, not shown, during rotation of the gear 20. It will be readily understood that during a single revolution of gear 20 the tone arm 16 is moved to an out of the way position adjacent the turntable, and the lowermost record in the record stack on spindle 19 is ejected for movement to the turntable. The record change mechanism for accomplishing this forms no part of the present invention, and any conventional means may be used.

An upright flange 43 is provided on the right hand end of the lower plate 28, and as gear 20 begins to rotate because of the engagement of its teeth with the teeth 15 on hub 13, the flange 43 is moved into engagement with a reset cam 44 extending downwardly from motorboard 10. The reset cam moves the operating

plates

28 and 31 to the right as viewed in the drawing as the gear 20 continues to rotate until the surface 38a in the notch 28 of upper plate 31 engages hub 21 and lower plate 28 moves to the right with respect to the upper plate 31 to reset the clutch defined by spring 33. At this point, the pawl 23 will be disposed in non-operating position within the confines of gear 20 and the elements of the trip actuating mechanism will be in position for starting another record change cycle.

I claim:

1. In a record changer, a motorboard rotatably mounting a turntable, a tone arm movably mounted on the motorboard and adapted to track a record having a lead out groove for accelerated movement of said tone arm. at the end of record play, a drive gear rotated by said turntable and having a striker, a driven gear normally out of mesh with said drive gear and movable into mesh therewith for rotation thereby to effectuate a record change cycle, and velocity trip means for bringing the drive and driven gears into mesh comprising, a pawl pivotally mounted on the driven 'gear and having a camv surface and a detent surface each movable to 'a position to be engaged by said striker, first and second links mounted for rectilinear movement on said driven gear, said second link being mounted for movement relative to said first link, clutch means retaining said first and second links for movement together, means on said second link making rolling and sliding contact with said pawl to pivot the same, and means for transmitting movement of the tone arm through said first and second links to the pawl, whereby said movement transmitting means moves said pawl cam surface into engagement with said striker and said striker moves said pawl and said second link relative to said first link upon each revolution of said turntable until said tone arm tracks said lead out groove whereupon the accelerated movement of said tone arm is transmitted through said movement transmitting means and said links to said pawl to move said pawl detent surface into the path of travel of said striker and move said drive and driven gears into mesh.

2. In 'a record changer, a motorboard rotatably mounting a turntable, a tone arm movably mounted on the motorboard and adapted to track a record having a lead out groove for accelerated movement of said tone arm at the end of record play, a drive gear rotated by said turntable and having a striker, said drive gear having teeth around the outer periphery thereof, a driven gear having teeth around the outer periphery thereof normally out of mesh with the teeth on said drive gear and movable into mesh therewith for rotation of said driven gear by said drive gear to effectuate a record change cycle, and velocity trip means for bringing the teeth on drive and driven gears into mesh comprising, a pawl pivotally mounted on the driven gear and having a cam surface and a detent surface, said pawl being movable from a non-operating position within the periphery of the driven gear to an operating position wherein the detent surface of the pawl is outside of the periphery of the gear in position to be engaged by said striker, first and second links mounted for rectilinear movement on said driven gear, said second link being mounted for movement relative to said first link, clutch means retaining said first and second links for movement together, means on said second link making rolling and sliding contact with said pawl topivot the same, and means for transmitting movement of the tone arm through said first and second links to the pawl, whereby said movement transmitting means moves said pawl toward said operating position to move said pawl cam surface into engagement with said striker, and said striker moves said pawl and said second link relative to said first link upon each revolution of said turntable until said tone arm tracks said lead out groove whereupon the accelerated movement of said tone arm is transmitted through said movement transmitting means and said links to said pawl to move said pawl detent surface into said operating position wherein said detent surface is in the path of travel of said striker and engagement of said pawl by said striker moves the teeth on said drive and driven gears into mesh.

3. In a record changer, a motorboard rotatably mounting a turntable, a tone arm movably mounted on the motorboard and adapted to track a record having a lead out groove for accelerated movement of said tone arm at the end of record play, a drive gear rotated by said turntable and having a striker, said drive gear having teeth around the outer periphery thereof, a driven gear having teeth around the outer periphery thereof normally out of mesh with the teeth on said drive gear and movable into mesh therewith of said driven gear by said drive gear to effectuate a record change cycle, and velocity trip means for bringing the teeth on drive and driven gears into mesh comprising, a pawl pivotally mounted on the driven gear and having a cam surface and a detent surface,

said pawl being movable from a non-operating position within the periphery of the driven gear to an operating position wherein the detent surface of the pawl is outside of the periphery of the gear in position to be engaged by said striker, first and second links mounted for rectilinear movement on said driven gear, said second link being mounted for movement relative to said first link, clutch means retaining said first and second links for movement together, means on said second link making rolling and sliding contact with said pawl to pivot the same, means for transmitting movement of the tone arm through said first and second links to the pawl, whereby said movement transmitting means moves said pawl toward said operating position to move said pawl cam surface into engagement with said striker, and said striker moves said pawl and said second link relative to said first link upon each revolution of said turntable until said tone arm tracks said lead out groove whereupon the accelerated movement of said tone arm is transmitted through said movement transmitting means and said links to said pawl to move said pawl into said operating position wherein said pawl detent surface is in the path of travel of said striker and engagement of said detent surface by said striker moves the teeth on said drive and driven gears into mesh, and means for resetting said pawl to non-operating position after the teeth on said drive and driven gears have moved into mesh including a portion of said motorboard engageable with said first link.

4. A record changer as defined in claim 3 wherein said links are positioned in facially opposed relationship with respect to one another, and said second link includes a longitudinal slot with a portion of said first link extending into said slot to mount said links for movement relative to one another.

5. A record changer as defined in claim 4 wherein means are provided on said driven gear for guiding said links in their rectilinear movement.

References Cited UNITED STATES PATENTS 8/1959 Vistain 274l0 8/1962 Guest 2741.ll

Claims

1. IN A RECORD CHANGER, A MOTORBOARD ROTATABLY MOUNTING A TURNTABLE, A TONE ARM MOVABLY MOUNTED ON THE MOTORBOARD AND ADAPTED TO TRACK A RECORD HAVING A LEAD OUT GROOVE FOR ACCELERATED MOVEMENT OF SAID TONE ARM AT THE END OF RECORD PLAY, A DRIVE GEAR ROTATED BY SAID TURNTABLE AND HAVING A STRIKER, A DRIVEN GEAR NORMALLY OUT OF MESH WITH SAID DRIVE GEAR AND MOVABLE INTO MESH THEREWITH FOR ROTATION THEREBY TO EFFECTUATE A RECORD CHANGE CYCLE, AND VELOCITY TRIP MEANS FOR BRINGING THE DRIVE AND DRIVEN GEARS INTO MESH COMPRISING, A PAWL PIVOTALLY MOUNTED ON THE DRIVEN GEAR AND HAVING A CAM SURFACE AND A DETENT SURFACE EACH MOVABLE TO A POSITION TO BE ENGAGED BY SAID STRIKER, FIRST AND SECOND LINKS MOUNTED FOR RECTILINEAR MOVEMENT ON SAID DRIVEN GEAR, SAID SECOND LINK BEING MOUNTED FOR MOVEMENT RELATIVE TO SAID FIRST LINK, CLUTCH MEANS RETAINING SAID FIRST AND SECOND LINKS FOR MOVEMENT TOGETHER, MEANS ON SAID SECOND LINK MAKING ROLLING AND SLIDING CONTACT WITH SAID PAWL TO PIVOT THE SAME, AND MEANS FOR TRANSMITTING MEANS MOVES SAID TONE ARM THROUGH SAID FIRST AND SECOND LINKS TO THE PAWL, WHEREBY SAID MOVEMENT TRANSMITTING MEANS MOVES SAID PAWL CAM SURFACE INTO ENGAGEMENT WITH SAID STRIKER AND SAID STRIKER MOVES SAID PAWL AND SAID SECOND LINK RELATIVE TO SAID FIRST LINK UPON EACH REVOLUTION OF SAID TURNTABLE UNTIL SAID TONE ARM TRACKS SAID LEAD OUT GROOVE WHEREUPON THE ACCELERATED MOVEMENT OF SAID TONE ARM IS TRANSMITTED THROUGH SAID MOVEMENT TRANSMITTING MEANS AND SAID LINKS TO SAID PAWL TO MOVE SAI D PAWL DETENT SURFACE INTO THE PATH OF TRAVEL OF SAID STRIKER AND MOVE SAID DRIVE AND DRIVEN GEARS INTO MESH.