US2259251A

US2259251A - Tone arm trip mechanism for automatic phonographs

Info

Publication number: US2259251A
Application number: US313732A
Authority: US
Inventors: John C Kamp
Original assignee: Wurlitzer Co
Current assignee: Wurlitzer Co
Priority date: 1940-01-13
Filing date: 1940-01-13
Publication date: 1941-10-14
Anticipated expiration: 1958-10-14

Description

Oct. 14, 1941. J. c. KAMP 2,259,251

TONE ARM TRIP MECHANISM FOR AUTOMATIC PHONOGRAPHS Filed Jan. 13, 1940 3 Sheets-Sheet 1 INVENTOR ATTORNEY Oct. 14; 1941. J. c. KAMP 2,259,251

TONE ARM TRIP MECHANISM FOR AUTOMATIC PHONOGRAPHS Filed Jan. 13, 1940 3 Sheets-Sheet 2 INVENTOR ATTORNEY Ocf. 14, 1941. J. c. KAMP 2,259,251

TONE ARM TRIP MECHANISM FOR AUTOMATIC PHONOGRAPHS Filed Jan. 13, 1940 3 Sheets-Sheet 3 INVENTOR ATTORNEY l atentecl Oct. 14, 1941 TONE ARM TRIP MECHANISM FOR AUTO- MATIC PHONO GRAPHS John C. Kamp, Buffalo, N. -Y., assignor to The Rudolph Wurlitzer Company, North Tonawanda, N. Y., a corporation of Ohio Application January 13, 1946, Serial No. 313,732

12 Claims.

This invention relates generally to certain new and useful improvements in automatic phonographs, but more particularly to a tone arm trip mechanism therefor.

It has for one of its objects to provide a tone arm trip mechanism for use with records employing the eccentric lead-in or terminal groove that will positively control the arresting of the phonograph upon the second inward movement of the tone arm after its stylus has engaged the eccentric tripping groove of disk phonograph records.

Another object is the provision of a mechanism of this character which embodies a novel arrangement of trip-governing pawls and levers functioning to initially prepare the mechanism for tripping on the initial engagement of the tone arm stylus with the terminal groove and the actual tripping of such mechanism on the second engagement of the stylus with such groove.

A further object of the invention is to provide a tone arm trip mechanism which is simple, compact and inexpensive in construction, reliable in operation and whose parts are not liable to get out of order.

Other features of the invention reside in the construction and arrangement of parts hereinafter described and particularly pointed out in the appended claims.

In the accompanying drawings:

Figure 1 is a fragmentary horizontal section of an automatic phonograph showing my improved tone arm trip mechanism applied thereto, the parts being in play position. Figure 2 is an enlarged fragmentary top plan view, partly in section, of the tone arm trip mechanism and associated parts, shown in a play position. Figure 3 is a similar view with the parts in the position when the needle of the tone arm initially encounters the eccentric tripping groove of the record. Figure 4 is a like view with the parts in a tripping position to arrest the playing of the phonograph when the needle of the tone arm is on its second inward swing into the eccentric tripping groove of the record. Figure 5 is a fragmentary top plan view of a difierent tone arm assembly showing a modified form of tone arm trip mechanism applied thereto. Figure 6 is a fragmentary side elevation, partly in section, of the trip mechanism in a play position. Figure 7 is a similar view with the parts in a position after the tone arm needle has initially encountered the eccentric lead-in groove of the record. Figure 8 is a view, similar to Figure 7, with the parts in a position after completion of an outward swing of the tone arm. Figure 9 is a similar View with the parts in a tripped position which has been accomplished by the secondinward swingiof the tone arm needle in the eccentric tripping groove.v Figure 10 is 'a fragmentary side elevation, partly in section, of another modified form. of the invention, the parts being shown in a play position. Figure 11 is a similar view with the parts in a position after the tone arm has initially encountered the eccentric groove of the record. Figure 12 is a similar view with the parts in a tripping position efiected on the second inward swingof the tone arm. i

Similar characters of reference indicate corresponding parts throughout the several views.

This improved tone arm trip mechanism has been designed more particularly for use with automatic phonographs of the multi-record type, so that after a given record has been played and, the tone arm stylus enters the customary terminal or lead-in groove in the record, the recordchanging mechanism of the phonograph will be initiated or automatically rendered operative to lift the tone arm from the played record and restore it to a position at one side of the turntable, andalso remove the played record from the turntable, whereby the parts will assume a position to play the next record. In'the embodiment .of the invention shown in Figures 1-4, inclusive, the same has been shown by way of example in connection with a phonograph mechanismof the type shown in the pending Wright application Serial No. 267,833, wherein the records are supported in a stack on a turntable l5 applied to a spindle i6, and are adapted to be individually elevated after play to a position above the stack to provide an operating or playing clearance for the'to'ne arm ll, the elevating mechanism being indicated generally by the numeral I8 and being actuated at a predetermined time in the cycle of operations of the phonograph by an operatingcam l9 applied to a shaft 20 disposed in parallel relation to the turntable spindle l6.

Briefly stated, the means for transmitting motion to the cam I9 at predetermined times to automatically govern the record-changing cycle as well as to control the movement of the tone arm to a position at one side of the turntable, are constructed as follows:

' Loosely mounted on the lower end of the turntable-spindle I6 is apinion 2| which constantly meshes with agear 22 constituting a part of the cam l9. Attached toithis pinion is a disk or circular plate 23 on which a horizontally-swinging clutching pawl 24 is pivoted for releasable coupling engagement with one or another of an annular row of notches 25 formed in a collar 26 fixed on the turntable-spindle alongside said disk. A spring 21 is connected to this pawl for constantly urging it into clutching position shown in Figured, which is the record-changing position. When the pawl is in its clutched position, motion is transmitted from the spindle to the collar and thence through the pawl and disk to the pinion 2| and gear lite rotate, the. cam

in a counter-clockwise direction viewing Figure .1 During the record-changing cycle, this cam makes one revolution and during this timethetone I1 is lifted from the played record and to,

one side of the turntable and the record-elevating mechanism actuated to liftthe played record from the stack and expose the next record, for

play. When the tone arm reaches the end of playing a givenrecord, it. initiates a. mechanism for. causing the clutching pawl 24 to engage the notched collar ZS-to transmit motion to the gear 22; anditsassociated cam l9. Normally, that is,- during. the playing of a record, thisclutching paw-lis. heldin the releasedposition, shown in Eig-ures.1, 2 and 3, by atappet lever 28 pivoted intermediate its ends at 29 and having a lug 38 at. its..-inner enddisposed incooperative relation 'withthe free end of the clutching pawl and a h1g3] at, its outer end releasahly engageable with apart ofgthe trip mechanism.for holding the tappet lever in its clutch-releasing position. A spring 32. connected to such lever normallyurges it toswingin a direction to free its lug. Sit-from the clutching pawl and; permit. the spring 21 connected'to the pawl to urgethe latter into its clutching. position.

The trip mechanism, in the embodiment of .the

invention shown in Figures 14, inclusive, is operatively associated with the. clutch-controlling tappet lever 28., and is preferably construotedas. follows:

Mounted. on the tone arm pivot-shaft 33 to turn therewithis a segmental plate 34. having atits periphery a row. of teeth 35 with which companion pawls 35 and 31- are adapted to cooperate for initiating the tripping of the" tappet lever 23, to a clutching position, These pawls, are mounted on companion independentlyemow.

able levers 38 and 39, respectively, which are superposed oneon. the other for horizontallyswinging movement on a. common upright pivot 4.11 so as. to rock toward and fromthe toothed edge of the segmental plate 34. The lever 33 audits pawl 36. constitute .apre-govern ing unit for the companion tripping lever 39 and its pawl 31, the pawl 35 encountering the toothed segment. 3.4 on the initial registration of the tone.

arm stylus. with the eccentric groove of the recordand the pawl 31 being subsequently brought.

into ..engagement. with such segment for. effecting the, tn'p. operation on the second encounter of the stylus with such groove. The inner end of the lower lever 33 extends slightly. beyond the corresponding end ofv thecompanion lever 39. and the respective pawls 36' and.3'l are pivoted adja-v cent-such ends, each pawl including av spring 4.l

forurging-it to pivot. toward the toothed edge of;

the segmental plate. Springs-4 2 and 43LCOI1? nected-tothelevers38 and 39, respectively, tend normally to rock the inner or pawl-bearing ends of: said levers toward the toothed edge. of the segmentalplate, the outer arm of. the upper.

7 side of the turntable.

latching or trip-actuating lever 39 having a latching notch or shoulder 44 therein with which the lug 3| of the tappet lever 28 is adapted to interlock during the playing cycle of the phonograph, and which notch is released from such tappet lever at the end of the playing cycle, when said lever 39 is tripped, to initiate the operation of the recordechanging mechanism and the restoration of the tone arm to a position at one The companion lower or trip-governing lever 38 has a pin 45 rising therefrom in engagement with a circumferential slot 46 formed in the lever 39, so that in the latched position of the tappet lever 26 with the notch 44 of the trip-actuating lever 39, the latter is held against movement out of the position shown in Figure 2 and the companion lever 38 is limited in its movement toward the segmental plate 34 by itspin 45 abutting the end of the lever-slot 46. Furthermore, the inner end of the lever 38 isprovided with. asecond pin or projection 47, which, inv the position of the parts shown in Figure 2; engages the trip-actuating pawl 37 and holds it against the tension of its spring H in a position where .it is clear of the path of travel of the segmental plate teeth 35 during the playingoycle, of the-phonograph. In this position of the. parts. shown in Figure 2, it will be also noted that. the. companion trip-governing pawl 36 is disposedfor engagement with the teeth of the se mental plate 3.4, when the latter is swung inwardly, as when the tone arm stylus first registers with the eccentric lead-in groove of the record, in readiness to prepare for the tripping operation.. The l ve 39 hogan eXtension at its inner endagainst which the pin 4'! is adapted to abut when. e com a n lever 8. been brought to a governing position resulting from its pawl. so being engaged with the teeth of the se menta p ate 34 as. show n Figure Th opera ion o h s t p a sm is s fol ows;

During the playing of the record, the segmental plate 34 moves inwardly with the tone arm fromthe f l e si o to h dotted ne pos tion s o n nF eure nd as the tone a m. st lus. te the ce c eadro e of the record, for the first time, one or another of the teeth 35 is engaged with the trip-governing pawl 35. Asthe stylus moves outwardly due to theeccentrieity of the lead-in groove, the plate this. movedinalilse ir t on ndih pawl 3a iscaiuSBd to be rocked about its pivot toward a dead center line position, shown in Figure 3, resuitin n a pr ss r b in ex r ed e lever sate roc it abou hon H0 bring s 1 ll-ou o o tact i h t e i -act a n pawl s-lxandinto en a eme t w t the ex en i n 4 0f the. com anion lev r 39- Wh n his. ak s p a the. trip-actua in pawl 7. o e by s spring Min a. direction to bring it into engagementv with thetoothed segmental plate '34, as likewise. shown in Figure. 3. on. he ne t o s ond inward travelofthe, tone arm and plate 34 eliectedby the. eccentric lead-in groove of the record, the pawl 31, is caused to rock from the positionshown in Figure 3, to the dead center line. position shown in Figure 4, resulting in a pressure eing ex rted on he trip-actuating m osit n ho n in i re wherein the pawl 24 is in clutching engagement with the notched collar 26.. This results in motion being transmitted to the gear 22 for initiating the actuation of the record-changing and tone arm restoring mechanism.

The restoration of the tone arm to its initial or non-play position at one side of the turn-v table may be effected in any appropriate manner, as by a horizontally-swinging bell crank lever 53 fulcrumed at 50 at one side of the gear 22 and having the arm thereof disposed in the path of travel of the face 52 of the cam 19,

while its other arm is connectedby a pin and

slot connection

53, 54 with the segmental plate 34, as shown in Figure 1. By this construction, as the cam encounters the lever arm 5| it gradually rocks the same in a direction to swing the plate 234 outwardly to in turn swing the tone arm to its non-play position. Subsequent to this operation, the cam l9, through suitable connections to the record-elevating mechanism I8, effacts the movement of the played record from the turntable and places the parts in position for playing the next record.

The trip mechanism is also adapted to function with the concentric type of lead-in record groove, and for this purpose the segmental plate 34 carries a depending pin 55 which is adapted to engage a lateral arm 56 projecting from the inner end or the trip lever 39, so that when the tone arm is swung inwardly into the concentric lead-in groove, such pin encounters the arm 53 and rocks the trip arm in a direction to release its notch from the lug 3| of the tappet lever 28.

In the modified form of the trip mechanism depicted in Figures 5-9, inclusive, the same has been shown with a tone arm assembly of the type disclosed in the Wright pending application Serial No. 262,704, the numeral 5! indicating a radial arm of the assembly which moves in unison with the tone arm, and 58 a stationary plate or platform disposed below said arm and having a pivot-lug 59 rising therefrom beyond the outer end of the path of travel of the arm, as seen in Figure 5. The part or tappet lever of the phonograph which is adapted to be tripped and springurged to a released position for initiating the operation of the record-changing mechanism and the restoration of the tone arm to its initial non-play position, is indicated by the numeral 69 and is shown in guiding engagement at its free end in a horizontal slot 6! formed in a lug 62 rising from the plate 58.

The latching of the tappet lever 56 is effected by a vertically-swinging trip lever 63 pivoted intermediate its ends at 64 to the plate-lug 59, the outer arm being provided at its lower edge with a latching shoulder 65 against which one end of the tappet lever is adapted to engage. Leading from this shoulder is a downwardly-inclined cam portion 66 which is adapted to engage the top side of the tappet lever in the unlatched position thereof, as when initiating the operation of the record-changing mechanism. The inner arm of the trip lever is provided at its top edge with a row of teeth 61 and is provided at the extremity thereof with a laterally-bent trip lug 68 which is disposed in the path of travel of an inclined tappet lug 69 pending from the arm 51 for effecting the actuation of the trip lever in a direction to unlatch it from the tappet lever, when a record having the concentric type of groove is used. A spring ID is connected to the trip lever to normally urge it into latching engagement with the tappet lever. Also pivoted at 64 in substantially parallel relation to the trip lever is a trip-governing or dummy lever H having a row of teeth 12 at its upper edge and which in length is shorter than the companion toothed arm of the trip lever. A spring 13 connected to this dummy lever normally maintains it in parallel relation with the trip. lever and a lug 1-1 projecting from the inner end of the dummy lever and adapted to bear against the adjoining top side of the platform 58 limits the upward swing of such lever.

Arranged for cooperation with the toothed levers.83 and H for controlling the tripping of the lever 63 when the tone arm stylus encounters, for the second time, the eccentric lead-in groove of the record, arepawls 15 and 16, respectively, these pawls being pivoted at Ti and 18 for vertical-swinging movement to the outer end of the radial arm 51. The pawl 15 has an arm 19 extending from the opposite side of the pivot T1 and associated with the pivot 18 of the companion pawl 16 is a bell crank 80, one arm of the latter having a pin 8] thereon which nor mally is in bearing contact with the top side of the pawl-arm 19, while the other arm of said bell crank has a pin 82 thereon which is normally in bearing contact with the underside of the pawl 16, as shown in Figure 6. A stop pin 83 projecting from the outer end of the arm 51 limits the upward movement of the pawl 15 during the time that the bell crank pin BI is in engagement with the pawl-arm 19, as shown in Figure 6. When the bell crank 89 is moved out of engagement with the pawl arm 19, the pawl I5 is then free by its own weight to move downwardly into engagement with the teeth of the trip lever 62, as shown in Figure 7.

In the position of the parts shown in Figure 6, the arm 51 is moving inward with the tone arm stylus about to engage, for the first time, the lean-in groove of the record. In this position of the parts it will be noted that both

pawls

15, 16 are in their normal position clear of the companion toothed levers 63 and TI. As the tone arm stylus traverses inwardly of the eccentric groove, the arm 5'! is smartly moved inwardly and the pawl 16 is brought into engagement with the teeth of the dummy lever H. As the arm 51 moves outwardly during the balance of the initial eccentric stroke, as shown in Figure '7, the pawl 16 is carried over a dead center position and presses downwardly on the companion lever H. At the same time the bell crank is moved clear of the pawl-arm T9 and the pawl 15 is free to drop by gravity into engagement with the teeth of the trip lever 63. Figure 8 shows the position of the parts when the tone arm stylus reaches the outermost portion of the eccentric groove in the record on the initial eccentric stroke and just prior to the movement of the arm 5'! in the opposite direction on the second eccentric stroke. When moved in this direction the pawls 15, F6 are both swung to or slightly beyond a dead center line position, resulting in both companion levers 63 and H being simultaneously depressed to the position shown in Figure 9, in which position the trip lever 63 is released from latching engagement with the tappet lever 60, causing the latter to be spring-urged to a position for actuating th'e record-changing mechanism and to effect the restoration of the tone arm to a position at one side of the turntable. In the released position of the tappet lever 60, its top face engages the inclinedcamface 65. on the trip lever 63and maintains the latter depressed to enable the pawls l5 and T5 to gravitate totheir initial positions shown in-Figure 6 as soonasthe retrograde movement of the tone arm has moved them from engagement with theteeth of their respective levers.

In this form of the invention, when the record contains the concentric type oilead-in groove, the tappet lug 69- on thearm 5'! encounters the lug 68 on the triplever 63 to accomplish the tripping operation and release the tappet lever 60 from the trip lever-shoulder 65.

In the modified form of the invention shown in Figures 10-12, inclusive, a single trip lever 3 is releasablyengageable at one end with the tappet arm 68 and. provided in the top edge of its other arm with-a rowof teeth85, a spring 38 serving to normally urge-saidlever toits latching position shown in Figures lo and 11 Mounted on the end-of theradial arm fil lare companion pawls 8 88: pivoted side by side and both adapted for; engagementwith the lever teeth 85. The pawl- 81; is-pivoted to-one arm of a rock lever 89,-wh-ile the pawl 88 has an arm 90 arranged to engage the opposing arm fil-of the rock lever 89. A step pin 92 serves to limit the downward swingingmovement of the rock lever. As the tone arm moves inwardly, the pawl 82 eventually encounters and-rides over the teeth of the trip lever 84 and, when the tone arm stylus encounters the lead-in groove-of the record and compels the tone arm tomoveoutwardly, the pawl 8l is carried to or past its dead center position, causingthe rock arm 89-to pivot upwardly to, the PQSition shown in Figure 11 and correspondinglycausi-ng itsarm fittorock the companion pawl 88 into engagement with the teeth of the trip lever. As the arm 51 is again moved inwardly in response to the movement imparted thereto by the eccentric groove in the record, such pawl 83 is moved toward its dead center position and'in so doing depresses the trip lever to its tripping or released position shown in Figure 12 I claim as my invention:

1. A tonearm trip mechanism for use with records of the eccentric terminal groove type, comprising a tripmeansadapted to be tripped from a. latching to an unlatching position, and

means including dualtripp-ing elements operatively engaging said trip means, one of said elements being disposed for pre-setting the trip means on the initial movement oi the tone arm by the eccentric groove of the record in readiness vfor a tripping operation and the companion trippingelement being disposed. for initiating the effective tripping operation oisaid trip means on the next eccentric-actuatedmovement of the tone arm.

2. A tone arm trip mechanism for use with records of the eccentric terminal groove type, comprising a latch adapted to be tripped from a normally latched to an unlatched position, a

member connected with the tone arm for movement therewith relative to saidlatch, and dual pawls dispqsed'in correlation and operatively interposed between said memberandthe latch for governing tripping movements, one of-said pawls constituting a prehsetting element for actuating the companion paw-l, during the first iii-movement of the tone arm by the eccentric groove. of the record, to a position in; readiness for a trippingoperation on a subsequent in;- movement of the tone arm in such-groove.-

'members, one of said pawls being engageable with oncor another of the teeth on the initial in=movementof the tone arm by the eccentric i groove of-the. record for presenting the other pawl, into pre-setting engagement with said teethwhereby. to render such other pawl, on a subse uentin-movement of the. tone arm, operative to actuate the latch member to a tripping position.

4. A tone. arm trip mechanism for use with 1 recordsof the. eccentric terminal groove type, comprising opposing relatively movable members, one of said members being adapted for connection with the tone arm for oscillatory movement therewith and the other constituting a latch adapted to be tripped from a latched to anunlatched position, and means for tripping said latch member including a row of teeth applied tov one. of. said members and aplurality oicorrelated pawls. associated with the. other of said members, one. of said pawls being normally position d in the path of the toothebcaring memher to be engaged thereby on the initial inmovement of the tone arm by the eccentric groove of. the. record and having an operative connection to the. other pawl for normally retaining it out of. the path of said tooth-bearin member and for presenting itinto engagement with such member at a. predetermined time in the initial in-movement of. said .arm, whereby to render said other pawl, on a subsequent. inmovement oi the tone arm, operative. to actuate the. latch member to, atripping position.

5.. Atone. armtrip mechanism for use. with records of the. eccentric terminal/groove type, comprising. opposing relatively movable members, onecf said members being adapted for connectionwith the .tone. arm for oscillatory movement therewith and the other constituting a latch adapted to be. tripped from a latched to an unlatched position, and means for actuating said latch member to. atripping position including a toothed rackapplied to one of said membersand a pair of pawls operatively associated with the otheroi. said members in opposing relation to thetoothed rack for engagement therewith, and meansmovably .actuated by one of said pawls in response .to its engagement with saidrack on the first iii-movement of the tone arm by the eccentric groove of the record, and operatively connected to the other of said pawls for presenting it into engagement with said rack, said second-named pawl, on the next in-movement of the tone arm exerting a displacement of the latch member to a tripping position.

6. A tone arm trip mechanism for use with records of the eccentric terminal groove type, comprising opposing relatively movable means, one of said means being adapted for. connection with the tone arrnfor oscillatory movement therewith-.and-the other being pivoted for displacement to and from a latching position, lever means o-peratively associated; withv one of said movable means andhaving pawls. connected thereto for cooperating engagement with a toothed rack applied to the companion movable means, said lever means including inter-engaging elements for effecting a displacement of one of the lever means, when its pawl engages said rack on the first in-movement of the tone arm by the eccentric groove in the record, to cause the pawl on the companion lever means to be presented to said rack, whereby on the next inmovement of the tone arm said pivoted movable means is tripped to an unlatching position.

7. A tone arm trip mechanism for use with records of the eccentric terminal groove type, comprising a pivoted latch member adapted to be tripped from a latched to an unlatched position, a member adapted for connection with the tone arm for oscillatory movement therewith, cooperating pawl and toothed means operatively associated with said members for effecting a tripping of the latch member at a predetermined time in the in-movement of the tone arm by the eccentric groove in the record, and lever and pawl means operatively connected to one of said members for movement relative thereto and including a part releasably engageable with said latch-tripping pawl for normally retaining it clear of its cooperating tooth means, the pawl of said lever and pawl means being operatively engageable with said toothed means on the first in-movement of the tone arm to effect a displacement of its lever means in a direction to cause the latch-tripping pawl to engage said toothed means and trip said latch member on the next in-movement of the tone arm.

8. A tone arm trip mechanism for phonographs, comprising a member adapted for connection with the tone arm for oscillatory movement therewith and having teeth thereon, and a pair of latch-governing levers pivoted for movement relative to said member and each including a pawl adapted for engagement with the teeth of such member, one of said levers being normally positioned with its pawl in the operating path of the teeth of the tone arm member and including a part engageable with the pawl of the companion lever for normally retaining it out of the path of said teeth, said first-named lever being displaceable by its pawl about its pivot at a predetermined time in the tone arm movement to cause the pawl of the second-named lever to be engaged with the teeth of said tone arm member, said second-named lever being displaceable by its pawl to a tripping position at a subsequent time in the tone arm movement.

9. A tone arm trip mechanism for phonographs, comprising a member adapted for connection with the tone arm for oscillatory movement therewith and having ratchet teeth at its periphery, a latching lever pivoted for movement toward and from said toothed member and having a pawl engageable with the teeth thereof at a predetermined time in the tone arm movement for pivoting said pawl and the latching lever to a tripping position, and a second lever disposed in adjoining governing relation to the latching lever and having a pawl thereon engageable with said toothed member and a part engageable with the pawl of said latching lever for controlling its movement into trip-seeking engagement with said toothed member subsequent to the initial engagement of said second lever pawl with said toothed member.

10. A tone arm trip mechanism for phonographs, comprising a member adapted for connection with the tone arm for oscillatory movement therewith and having ratchet teeth at its periphery, a latching lever pivoted for movement toward and from said toothed member and having a pawl engageable with the teeth thereof at a predetermined time in the tone arm movement for pivoting said pawl and the latching lever to a tripping position, a spring connected to said lever for releasably retaining it in a latched position, a spring connected to said pawl for urging it into tripping engagement with said toothed member, and a second lever pivoted coaxially with said latching lever having a pawl thereon normally disposed in the path of the teeth of the tone arm member for engagement therewith and a part thereon engageable with the latching lever pawl for normally retaining it from engagement with such toothed member, said second lever pawl being displaceable by said toothed member to rock its lever in a direction to cause said latching lever pawl to be presented to said toothed member for actuation thereby to trip said latching lever to a released position.

11. A tone arm trip mechanism for phonographs, comprising a member adapted for connection with the tone arm for oscillatory movement therewith and having a pair of pivoted pawls thereon, a pair of levers pivoted in adjoining relation to said tone arm member and having ratchet teeth thereon for cooperating engagement with said pawls, respectively, one of said levers constituting a latching element including a spring connected thereto for releasably retaining it in a latched position and the companion pawl of the other lever being normally disposed for engagement with the teeth thereof, and means operatively connecting said last-named pawl with the latching lever pawl for governing the displacement of the latter into and out of engagement with the teeth of said latching lever.

12. A tone arm trip mechanism for phonographs, comprising a pivoted latching member having a spring connected thereto for releasably retaining it in a latched position, and means for actuating said latching member to a released position including cooperating, relatively-movable ratchet and pawl-bearing elements, the pawl of the latter being normally disposed for engagement with the ratchet to displace the pawl-bearing element to a pre-set tripping position during an initial relative movement of such parts, and a tripping pawl for the latching member normally disengaged from said ratchet and having an operative connection to said pawl-bearing element for governing its movement into engagement with the ratchet upon such initial movement or the parts, whereby upon a subsequent relative movement of the ratchet and pawlbearing element the tripping pawl is caused to displace the latching member to its released position.

JOHN C. KAMP.