US3760136A

US3760136A - Switching device for a tone band drive

Info

Publication number: US3760136A
Application number: US00218235A
Authority: US
Inventors: H Laufer
Original assignee: Dual Gebruder Steidinger GmbH and Co
Current assignee: DEWEK VEREINIGTE DEUTSCHE ELECTRONIC-WERKE GmbH
Priority date: 1971-01-28
Filing date: 1972-01-17
Publication date: 1973-09-18
Anticipated expiration: 1990-09-18
Also published as: DE2103953B2; DE2103953A1

Abstract

A switching device for driving of a tone band from an unwinding to a winding spool carrier, the end of said tone band being secured to said spool carrier of said unwinding tone band, which comprises drive means and a spool carrier. A drive shaft is provided for driving the spool carrier by the drive means. A disc fly-wheel mass is rotatably, but non-slidingly mounted on the drive shaft. A coupling means is disposed between the drive shaft and the disc fly-wheel mass for joining rotation of the latter. A member is adjustable against elastic means and rotatably, but non-slidingly mounted on said drive shaft. A shifting device for the member for shifting in dependency upon the transmission force of the coupling means against the force of the elastic means into an operative position, upon the transmission force being opposite as during an acceleration of the disc fly-wheel mass, and a switching device for stopping the drive, operable by the adjustable member, upon shifting the latter into its effective position.

Description

United States Patent [1 1 Laufer [111 3,760,136 [451 Sept. 18,1973

[75] Inventor: Helmut Laufer, St.

Georgen/Schwarzwald, Germany [73] Assignee: Dual Gebrueder Steidinger,

Schwarzwald, Germany 22 Filed: Jan. 17,1972

[21] Appl. No.: 218,235

[30] Foreign Application Priority Data Jan. 28, 1971 Germany P 21 03 953.2

[52] U.S. Cl. ZOO/61.13, ZOO/61.39 [51] Int. Cl. B65h 25 1hH01h 3 16 [58] Field of Search ..200/61.1361.l8, 33 R-38 E, 61.17, 61.39-61.41

.- [56] References Cited UNITED STATES PATENTS 2,314,748 3/1943 White 200/61.17 X 3,449,699 6/ 1969 Davin. 200/38 B 3,085,136 4/1963 Boyles 200/38 R 3,319,019 5/1967 J ullien-Davin 200/38 R 3,300,012 1/1967 White 200/38 A X 3,389,869 6/1968 Atsumi ZOO/61.13 X

3,263,038 7/1966 Walker ZOO/61.13

Primary Examiner-J. R. Scott AttorneyErnest G. Montague [57] ABSTRACT A switching device for driving of a tone band from an unwinding to a winding spool carrier, the end of said tone band being secured to said spool carrier of said unwinding tone band, which comprises drive means and a spool carrier. A drive shaft is provided for driving the spool carrier by the drive means. A disc fly-wheel mass is rotatably, but non-slidingly mounted on the drive shaft. A coupling means is disposed between the drive shaft and the disc fly-wheel mass for joining rotation of the latter. A member is adjustable against elastic means and rotatably, but non-slidingly mounted on said drive shaft. A shifting device for the member for shifting in dependency upon the transmission force of the coupling means against the force of the elastic means into an operative position, upon the transmission force being opposite as during'an acceleration of the disc flywheel mass, and a switching device for stopping the drive, operable by the adjustable member, upon shifting the latter into its effective position.

6 Claims, 2 Drawing Figures 1. SWITCHINGDEVICE FOR A TONE BAND DRIVE The present; invention relates. to av switching. device fora. tone band'drive, ingeneral, and to such tone band drive, whichmovesa tone band from an unwinding to a' windingcoihand the end of which is anchored with the. unwinding coil.

The switching device can be used for switching off thevdrive upon reachingthe end ofthe band or also for reversing tothe opposite driving direction. One of the previously knownswitching devices operates in such mannenthatthe tone bandis guided about a pin, which is: capable of swingingagainst the, action of a spring, whiehpin performs a. switching movement upon in crease of the band's tension, dueto reaching the band end. Such sensing elements which are in forced connection withflthetone band, may disturb the uniformity offthebandroperation and are not useable everywhere, inlconsideration offthe band operation, as for example, whenthe coils: or spoolsrare, disposed in a box.

Another known switchingdevice utilizes-the increase inthebandtension, for swingingtheentirecoil or spool in, its-. plane, for the purpose of obtaining a switching movement; Aside fromthe. fact, thatthis method requiresavery massive.construction, it isnot suitable for transportable instruments; due to the danger'of'faulty switchings: v I

Another: known switching-off'device is based on the fact-,that thespeedof theycoil is compared with the speedlof a member driven by a motor, more slowly so that; up,on stopping of the coil, areversal of the relative speed. occurs-between the'coil andthe slower driven member, which isthen also utilizedin turn for a switching; movement. Suchdevice necessitates.tosovercome constantly, a. friction, which, in addition to the disadvantageous influence onthe uniformity of the drive resultsin an undesired lossof'energy fora fast re-coiling, andfrequires: two switching-off'devicesfor both directions-of "the band movements in instruments with play operations.

It isrone object of thepresent invention, to provide a; simple switching device, which-iseffective in normal play; operation, aswellas: during fast re-coiling independently from the rotating directionof the coils, withouta; permanent additional loss in the drivingpower, due to friction, and which does notimpair the move ment uniformity of the tone band. during the play operation.

It is-another object" of the present invention, to provide; a, switching, device for a tone band drive, wherein adisc is=coupledto oneofboth coil shafts by interpositioninga catch, whereby thecatch shiftsa switching member for-the drive of I the tone band, uponstressing in-adirection opposite to the driving force of the swinging mass. I

With' theseand. other objects in view, which will become, apparent'in the; following detailed description, the present invention, which isshown by exampleonly, will beclearly understoodin connection with the accompanying; drawing, inwhich:

FIG. lisa. schematic bottom plan view-upon the bottom side ofiatone driving, device; and

FIG. Zis ailateral'sectional view along the lines 2--2, ofFlG. l. v

Referring now-tothe drawing, the device, designed in accordance with. the present invention, comprises a base'platelon which are mountedtwo coil shafts 2 and Satire upper.-ends.4 of-which are adapted-to engage the coil bodies or spool carries 5 of a tone band 6, which is located in a cassette 7. The coil shaft 3 is driven by means of a pair of gears Sand 9, an intermediate gear shaft 10, a friction coupling 11 with a belt pulley 12 and a belt 13, by means of a motor 14. The intermediate shaft 10 is mounted in a fork 15, which is capable of swinging about an axle 16. If the other coil shaft 2 is to be driven, the fork 15 is swung so far, until 'a gear 17, which meshes permanently'with the gear 9, and is also mounted on the fork 15, comes into engagement with a gear 18 of the other coil shaft 2. This drive is used to wind the tone band in both directions for the normal recording-and reproduction-operation. In the coil drive a slip clutch 11 is required, in order to be able to wind the tone band 6 which is pulled with constant speed by a tone shaft 19 with a pressure roll 20, upon a coil, which rotates with a reducing number of revolutions due to the increasing winding diameter. In order to effect a fast recoiling of the tone band 6, the pressure roll 20 is lifted from the tone shaft 19, and a friction wheel (not shown) of larger diameter than the gear wheel 9 and seated on the intermediate gear shaft l0,is also selectively coupled with the coil shafts 2 and 3 (through axial shifting).

The intermediate gear shaft 10 has a square section 21, on which a sleeve 22 is axially slidable. A disc flywheel 24, freely rotatable relative to the intermediate gear shaft 10, without being axially shiftable, is disposed above the sleeve. The sleeve 22 has at the upperfront side a saw-tooth shaped cam 29and is pressed by a spring 23'against a complementary formed recess into a collar 26 of the'disc fly-wheel 24, whereby the cam 29-presses against the face 28 of-the disc fly-wheel 24, which face is strongly inclined toward the radial plane upon acceleration of-the drive, the disc fly-wheel 24 is coupled with the coil shaft 3 in the direction of the driving movement.

shaft 3, and thus also the sleeve 22, are suddenly brought to a stop, due to the rigid connection of ,the

tone band end withthe coil body 5.

Since the fly-wheel 24 does not find great resistance on the cam 29, it continues to rotate due to its mass inertia, whereby the cam 29 is axially shifted against the force of the spring 23 from the less inclined face 25 of the disc fly-wheel 24. This movement is used for switching the drive, whereby the sleeve 22 shifts a switching member 27 of the conventionally known switching means (not shown) for the tone band drive, the conventionally known switching means being not part of the present invention. I

For a device for recordingand reproducingoperation, in such oppositely operation direction of the tone band, as disclosed by example, only one switching device is required, which is effective for fast recoiling as well as for normal operation. Whether the disc flywheel 24 is arranged on a shaft turning faster than the coil shaft, or on the coil shaft itself, depends upon the ratio of the lowest number of revolutions of the coil to the mass value of the disc fly-wheel 24. For portablemachines, a small, fast-runningdisc fly-wheel is, in any case, more favorable. Simultaneously, the rotating disc has a stabilizing effect upon the uniformity of the band pull in the recordingand reproducing-operations.

While I have disclosed one embodiment of the present invention, it is to be understood, that this embodiment is given by example only and not in a limiting sense.

I claim:

1. A switching device for driving of a tone band from an unwinding spool carrier to a winding spool carrier, the end of said tone band being secured to said unwinding spool carrier of the unwinding tone band, comprising drive means,

coil shafts for driving said spool carriers, respectively, by means of said drive means,

a freely rotatably mounted disc fly-wheel mass for stopping said drive means due to its mass inertia,

a coupling means operatively disposed between said coil shafts and said disc fly-wheel mass for joining rotation of the latter therewith,

said coupling means including a drive force transmitting member, shiftable into a first position cooperating with said disc fly-wheel mass for said joining rotation therewith, and into a second position shiftable out of joint rotation therewith,

elastic means biasing said member into joint rotation with said disc fly-wheel mass,

said coupling means including said member being operatively connected to said coil shaft for joint rotation therewith and being rotated by said drive means with said coil shaft, and said coupling means including said member being non-rotatable when said coil shaft is stopped by means of the end of said tone band stopping said winding spool carrier, said drive means being initially operative when said coil shaft is stopped via said end of said tone band, means cooperatively connected with said disc flywheel mass and said coupling means, for effecting, due to the mass enertia force of rotation of said disc fly-wheel mass, a shifting of said member in dependency upon a transmission moment force of said coupling means relative said disc fly-wheel mass and against the forceof said elastic means into said second position, upon said transmission force being opposite as during an acceleration of said disc fly-wheel mass, and stopping of rotation wherein said elastic means presses said member in axial direction towards said disc fly-wheel mass,

said member has a face engaging said disc fly-wheel mass and includes a cam extending in axial direction projecting beyond said face,

said disc fly-wheel mass has a recess complementary to said cam, and said cam and said recess constitute said shifting means,

an inclined face and a less inclined face on said cam, said inclined face constituting an abutment for said disc fly-wheel mass for joining the rotation of said coupling means and said intermediate shaft, and said less inclined face cooperating with said cam to effect an axial displacement of said member, upon a stopping of said one coil shaft, whereby said rotatably freely mounted disc fly-wheel mass axially displaces said member.

4. The switching device, as set forth in claim 2, further comprising a friction slip clutch coupling between said drive means and said intermediate shaft. 5. The switching device, as set forth in claim 2, further comprising means for selectively operatively driving either of said two coil shafts via said intermediate shaft. 6. The switching device, as set forth in claim 2, further comprising engagement thereof.

Claims

1. A switching device for driving of a tone band from an unwinding spool carrier to a winding spool carrier, the end of said tone band being secured to said unwinding spool carrier of the unwinding tone band, comprising drive means, coil shafts for driving said spool carriers, respectively, by means of said drive means, a freely rotatably mounted disc fly-wheel mass for stopping said drive means due to its mass inertia, a coupling means operatively disposed between said coil shafts and said disc fly-wheel mass for joining rotation of the latter therewith, said coupling means including a drive force transmitting member, shiftable into a first position cooperating with said disc flywheel mass for said joining rotation therewith, and into a second position shiftable out of joint rotation therewith, elastic means biasing said member into joint rotation with said disc fly-wheel mass, said coupling means including said member being operatively connected to said coil shaft for joint rotation therewith and being rotated by said drive means with said coil shaft, and said coupling means including said member being non-rotatable when said coil shaft is stopped by means of the end of said tone band stopping said winding spool carrier, said drive means being initially operative when said coil shaft is stopped via said end of said tone band, means cooperatively connected with said disc fly-wheel mass and said coupling means, for effecting, due to the mass enertia force of rotation of said disc fly-wheel mass, a shifting of said member in dependency upon a transmission moment force of said coupling means relative said disc fly-wheel mass and against the force of said elastic means into said second position, upon said transmission force being opposite as during an acceleration of said disc fly-wheel mass, and stopping of rotation of said member, and switching means for stopping said drive means, and operable by said member, upon shifting of the latter into said second position.

2. The switching device, as set forth in claim 1, which includes two of said coil shafts for driving said winding and unwinding spool carriers, respectively, an intermediate shaft relatively coupled with one of said coil shafts, selectively, for transmission of the speed of said intermediate shaft to a lower speed of said one coil shaft, said drive means for rotatably driving said intermediate shaft, said disc fly-wheel mass is freely rotatably but axially immovably mounted on said intermediate shaft, and said coupling means including said member is axially displaceably mounted on said intermediate shaft but mounted thereon for joint rotation therewith.

3. The switching device, as set forth in claim 2, wherein said elastic means presses said member in axial direction towards said disc fly-wheel mass, said member has a face engaging said disc fly-wheel mass and includes a cam extending in axial direction projecting beyond said face, said disc fly-wheel mass has a recess complementary to said cam, and said cam and said recess constitute said shifting means, an inclined face and a less inclined face on said cam, said inclined face constituting an abutment for said disc fly-wheel mass for joining the rotation of said coupling means and said intermediate shaft, and said less inclined face cooperating with said Cam to effect an axial displacement of said member, upon a stopping of said one coil shaft, whereby said rotatably freely mounted disc fly-wheel mass axially displaces said member.

4. The switching device, as set forth in claim 2, further comprising a friction slip clutch coupling between said drive means and said intermediate shaft.

5. The switching device, as set forth in claim 2, further comprising means for selectively operatively driving either of said two coil shafts via said intermediate shaft.

6. The switching device, as set forth in claim 2, further comprising first gear means secured to said intermediate shaft, second gear means secured to each of said two coil shafts, and a pivotal fork, on which said first gear means is disposed, is pivotally mounted for selective engagement of said first gear means with said second gear means of either of said two coil shafts for driving engagement thereof.