US3542312A

US3542312A - Web transport drive structure

Info

Publication number: US3542312A
Application number: US738966A
Authority: US
Inventors: Leif O Erickson
Original assignee: Minnesota Mining and Manufacturing Co
Current assignee: 3M Co
Priority date: 1968-06-21
Filing date: 1968-06-21
Publication date: 1970-11-24
Anticipated expiration: 1987-11-24
Also published as: AT299571B; DE1932274B2; DE1932274A1; DE1932274C3; GB1278685A; NL6908917A; FR2011969A1

Description

United States Patent 11113,542,312

[72] Inventor Leii'O. Erickson [50] Field of Search 242/ l 79- Little Canada, Minnesota 2Q] [2|] Appl. No. 738,966

[22] Filed June 21, 1968 References Cited [45] Patented Nov. 24, 1970 UNITED STATES PATENTS 1 Assignee Minnewta Mining and Manufacturing 2,304,913 12/1942 Herzig 242/181 g gszr Primary ExaminerLe0nard D. Christian a clorpogation Delaware Attorney-Kinney, Alexander, Sell, Steldt & Delahunt [S4] WEB TRANSPORT DRIVE STRUCTURE 12 Claims, 4 Drawing Figs.

[52] U.S.Cl 242/202 [51] lnt.Cl Bllb 15/32 G03b 1/04 ABSTRACT: A drive system for a web transport which utilizes a pair of spindles, each having a built-in slip clutch structure mounted for movement along their axes to afford selective frictional driving engagement with a driving member.

Patented Nov. 24, 1970 3,542,312

Sheet 3 of2 INVEN'I'UK ZE/F 0 fwc/rsa/v BY W W? M WEB TRANSPORT DRIVE STRUCTURE This invention relates to a web transport, and in one aspect to the spindle construction 'and novel mounting arrangement therefor, adapting the transport for recording machines or the like, and particularly recording machines and the like using cassettes. j

The present invention has wide application in the web transport art and particularly in tape recording and/or reproducing machines or film handling equipment, for example, cameras and projectors.

The present invention hasparticular advantage in web handling equipment where the web is contained in a cassette and wound on a pair of spools or reels rotatably positioned within the container and adapted to be positioned over and driven by two spindles but not solely supported by the spindles.

The present invention provides a spindle structure formed of a plurality of pieces which, when assembled, define a sup port for receiving and rotatably driving a spool, a slip clutch structure connecting the driving spool support with a driven member having a friction drive surfacedefined thereon, and a support permitting free rotational movement of the spindle about its axis and axial movement of the spindle.

The prior art is replete with tape drive systems for recording machines, cameras, projectors and the like, but it fails to teach the construction of a spindle according to the present inven-' tion. The spindle construction of this invention includes a spring-loaded clutch to significantly reduce the number of parts subject to wear, increase the life of the clutch and maintain during the life of the clutch a constant torque-transmitting force.

In the present invention the spindles are mounted for bodily movement along their axes to'move into and out of engagement selectively with a drive member. This affords a transport utilizing a pair of spindles to support the supply spool and the takeup reel in a manner to be selectively driven from the same drive member, thus simplifying the drive system and yet permitting searching as on prior known tape machines. The spindles being located to permit driving engagement of each spindle with the'drive member to achieve rotation in a winding direction. The drive system does not sacrifice any previously desired function but greatly reduces the number of pulleys, belts or idler rollers necessary to perform these functions. The spindles and the single drive member are compactly mounted to selectively drive the spindles in opposite directions.

The present invention has particularadvantage in machines where price and/or space limitations require a small number of components without jeopardy in machine performance or features.

The above and further advantages will be more fully understood after a perusal of the followingdetailed description which refers to the accompanying drawing wherein:

FIG. 1 is a plan view .of the tape transport of a magnetic tape machine formed in accordance with the present invention;

FIG. 2 is a plan view of one tape cassette adaptedfor use on in broken lines;

FIG. 3 is a fragmentary vertical sectional view of the transport of the machine of FIG. 1; and I FIG. 4 is a detail view of a portion of the transport of the machine shown in FIG. 1; the top plate having been removed.

Referring now to the drawings, a portion of a magnetic tape recording and/or playbackv device, commonly referred to as merely a tape recorder is illustratedincluding a transport designed in accordance with the present invention. The illustrated tape recorder transport is designed for use with a cassette 5, such as illustrated in FIG. 2, comprising a container 6 in which is journaled in spaced relation a pair of tape spools 7 and 8 and which is formed with guide members 9 and 11 directing the tape 12 from one spool to the other spool across one generally open side on one edge of the container. The container 6 is formed with a pair of

openings

13 and 14 adjacent the open side across which the tape is directed to receive a capstan of the recording machine against the inner face of the tape to afford movement of the tape 12. When a the machine of FIG. 1, indicating the path of the tape therein movement of the tape and to take up the tape after the same has been driven past the magnetic transducer or head 18 by means of the capstan 19 and pressure roller 21 as is conventional in tape recorders.

The spindles 16 and 17, the capstan 19, pressure roller 21 and magnetic head aresupported from a frame including a plate 22. This plate 22 is the primary support member supporting in a depending manner an electric motor 23 having a drive shaft 24 engaged by an idler roller 26 to transfer a rotational torque to the peripheral surface of a flywheel 27 rotatably supported on an axis generally normal to the plane of the plate 22, as more clearly illustrated in FIG. 3. This flywheel 27 drives the capstan 19 which advances the tape 12 by having the tape 12 pressed against the capstan by the spring-biased pressure roller 21.

The spindles 1.6 and 17 are freely rotatably supported from the underside of the plate 22 by

support brackets

28 and 29. These spindles are adapted to be received within the hubs of the spools 7-and 8 of the cassette and the capstan 19 is received in one of the

openings

13 or 14 in the cassette, thus positioning the tape12 between the capstan l9 and the pressure roller 21. The pressure roller 21 is movably mounted relative to the capstan by its support on a bar 31, which bar is slidably mounted projecting the plate 22. The bar 31 is generally L-shaped and is mounted on

guide pins

32, 33, and 34 for movement toward and away from the spindles 16 and 17 and capstan 19. This bar 31 supports the head 18 and an erase head 36 adjacent one edge, together with the pressure roller 21 which is rotatably mounted in a frame which in turn is supported by a pivot pin 37 and biased by a spring 38 toward engagement with the capstan 19. The freedom of movement of the pressure roller and frame is limited by another pin 39 projecting from the bar 31 through an enlarged opening in the frame for the pressure roller. The bar 31 is moved from a retracted out-of-the-way position to the play position (as illustrated in FIG. 1) under the control of a play key 41 pivoted about a key support shaft 42 mounted parallel to the plane of the plate 22. Key 41 imparts a clockwise pivoting action (as seen in FIG. 1) to a standard 43 pivoted on the plate 22 by a pin 44. The standard has a radially extending toggle arm 46.

carrying a pin connected to a link 47 forming a toggle connection, which when in the position shown in HO. 1, advances the bar 31, from a retracted position to the play position shown, through a floating link 48, connected at one end by a pin 49 to the bar 31 and extending through an enlarged slot 51 formed in an upturned flange 52 at the edge of plate 22. The link 48 has a tension spring 53 connected thereto and to the plate 22 which spring, in conjunction with the toggle link formed by arm 46 and link 47, positively advances or retracts bar 31 and holds it in each position. In the play position, the erase head 36 and recording head 18 are positioned in the edge wall of the cassette 5 and the pressure roller 21 is positioned against the tape 12, pressing it against the capstan 19.

It is also to be noted that with the toggle joint in the play I position the pivot point between link 48 and link 47 can act as a fulcrum. Thus by pulling the free end of link 48 (as by a sole noid.or lever, not shown, connected to the link at 55) against the bias of spring 53, the bar 31 can be retracted to interrupt or pause tape movement. This is also possible be merely retracting the bar 31 by direct pulling force. In either instance release of the link 48 or bar 31 places the machine back in play position.

against the spindle will stop any free rotation of the spindles. In the illustrated device each brake member 58 and 59 is pivoted about a pin 57 and is formed with a flange 60 defining the braking surface positioned for movement toward and away from the peripheral surface of the spindles. The braking surfaces 60 are urged into braking engagement by a compression spring 61 positioned between the two braking members 58 and 59 on the ends of the members opposite thesurfaces 60. Each braking member is also formed with at least one arm, identified as 62, 63, 64, adjacent the spring 61, which upon pivotal movement of one brake member relative to the other member will cause a subsequent pivoting movement of the other brake member to release the braking force on the spindles sequentially, first from the winding spindle and then from the unwinding spindle, or apply the braking force sequentially, first to the unwinding spindle and then to the winding spindle, in either direction of operation. The brakes are released upon movement of bar 31 to play position by an upstanding leg 66 on the bar engaging an extension 67 on the brake member 59. Leg 66 pivots the brake member 59 about its pivot 57 causing arm 63 to engage the arm 64 to then release brake member 58. Return of the bar 31 to the retracted position allows the braking force to be applied tothe spindles.

The takeup drive system is operated by movement of bar 31 to the play position. The flywheel 27, as seen in FIGS. 3 and 4, has an axial dimension greater than in most flywheels providing a cylindrical peripheral flange formed with beveled edges or driving

surfaces

68 and 69 and with a central axially extending hub 71 supported on the capstan shaft, which is suitably journaled in the plate 22 and by a bracket 72 extending beneath the flywheel and depending from the plate 22. An idler member for the takeup drive is operatively positioned between the hub 71 and the spindle 17 and includes a cylindrical member 73, frictionally engageable with the spindle l7, and a flange 74 frictionally engageable with the hub 71. The idler member is rotatably supported on a pivoted link 75,

which is supported from a guide member 76 pivoted to the underside of plate 22 on a pin 77 and formed with a pin 78 extending upward through a slot in plate 22 and into a hole in bar 31-. The extended end of pin 78 is connected to a spring 79 urging the guide member 76, link 74 and idler member into operative position upon movement of bar 31 to play position. The idler member is retracted against the bias of spring 79 from spindle 17 upon retraction ofthe bar 31, by engagement between bar 31 and pin 78.

The spindles 16 and 17 are similar and only spindle 17, illustrated in section in FIG. 3 will be described in detail. The spindle 17 is rotatably mounted on a shaft 81, which shaft is axially movable in its support bracket 29. The axial movement permits spindle 16 to engage the outer edge 69 of the driving member and rotation thereof in a clockwise direction and spindle 17 to engage the inner edge 68 affordingcounterclockwise rotation, as illustrated in FIG. 1, affording fast forward or reverse searching.

The spindle comprises a body member 82 rotatably supported on the shaft 81 and having a hub and radial flange 83 which supports a ring 84 of high friction material with a beveled outer periphery complimentary to the beveled edge of the flywheel to permit driving engagement therewith. The spindles have a built-in slip clutch, which is defined by a sleeve assembly rotatablysupported on the body member and frictionally driven by said clutch therefrom. The assembly comprises a sleeve 86 disposed about the hub of the body member 82, which sleeve 86 has an end engaging a pad 87 of friction material on the surface of the flange 83 opposite the ring 84 and a spool-supporting sleeve 91. The end of the sleeve 86 opposite the pad 87 is recessed and has spaced fingers 88 defining, with complimentary fingers 89 on the reel-supporting sleeve 91, a bayonet joint to join the sleeves 86 and 91 for coincident rotation. Sleeve 91 is retained on the shaft 81 and is positioned on the hub of body member 82, for relative rotation. by a cap 92 fitted on the body member. A compression spring 94 is disposed between the sleeve 91 and sleeve 86,

around the bayonet joint, to urge the sleeve 86 against the friction pad 87 to transfer the driving force from the body member to the sleeve 91 and to the spool or reel supported thereon. A retaining ring and/or washer 93 and a washer 96 restricts axial movement of the body member 82 relative to the shaft 81.

Vertical movement of the spindles 16 and 17 is controlled by a pair of pivoted

arms

98 and 99. The arms are pivoted about and axis 101 disposed between and normal to the axis of the shafts 81 and are formed with

plate members

102 and 103, respectively, which extend upward through openings I06 and 107 in the plate 22. The

arms

98 and 99 are also formed with

angled members

108 and 109 to extend under the shafts 81. On the arm 99, the member 109 is formed to extend from the plate member 103 into the hollow center portion of the flywheel 27 to extend beneath the shaft 81 of the spindle 17. The upstanding portions or

plate members

102 and 103, extending above the plate 22, are joined by a tension spring 111, which spring 111 brings the plate members together and causes

members

108 and 109 to move each of the shafts 81 upward against the bias of a spring 112. A spring 112; see FIG. 3) is disposed between the mounting bracket and a washer on each of the shafts 81 to bias the shafts and spindles 16 and 17 downward into engagement with the driving member. The upstanding plate members of the

arms

98 and 99 are also disposed on opposite sides of a pivot pin 113 which is thepivot for a rod 114 actuatable to selectively pivot either of the

arms

98 and 99 in a direction to permit the respective spindle to be lowered into engagement with a beveled edge of the flywheel. This is accomplished by movement of the rod 114 against the

plate member

102 and 103 which causes pivotal movement of the respective arm about the axis 101, dropping the angled member from beneath the associated shaft 81. Movement of the rod 114 and pivotal movement of the arm also causes the extended plate member of the arm to release the brake members by application of a force against a projection 116 causing the pivotal movement of the brake members away from the spindles.

Rotation of the rod 114 about the pivot 113 also causes actuation of a pivoted crank arm 117 which engages the stan' dard 43 causing it to be moved, if in the play position to the retracted position, such that upon forward or reverse searching the pressure roller will always be automatically retracted from the capstan 19 to prevent damage to the tape. Actuation of the crank arm 117 is afforded by cam means associated with rod 114 such as a cam 118 carried on the'rod 114 which is engaged with followers or cam surfaces on one end of the crank arm 117 causing it to be pivoted about the pin 119 upon the pivotal movement of the rod.

The movement of the spindles selectively into engagement with the

surfaces

68 and 69 0f the flywheel 27 cause these spindles to be rotated at an increased speed for the searching operation. In the illustrated device the spools 7 and 8 are driven from the ribs 120 (FIG. 3) extending radially from the sleeve 91 but the spools are supported by the container 6 of the cassette 5. The axial movement of the spindle therefore does not cause a similar axial movement of the spool. The application of this invention to a web transport using individual reels would require some additional support for the reel to prevent its axial movement along with the spindles to assure positive tracking and alignment-of the web with the reel.

Having thus defined the present invention by reference to a machine showing a preferred embodiment of the same it will be appreciated that various changes and modifications can be made herein without departing from the scope of the invention.

Iclaim: 1. In an apparatus for transporting a web, the combination of:

a pair of spaced spool-supporting spindles each having and axis and a peripheral drive surface; means supporting each said spindle for rotation about its axis and for independent axial movement; and

a circular driven member having a peripheral drive surface disposed along a path extending between the axes of said spindles and in'axially aligned spaced relation to the .drive surfaces of said spindles, said peripheral drive surface of said driven member being adapted to engage the drive surface of each spindle for driving said spindles upon axial movement of the same toward said driven member to place and drive surfaces in contact.

2. The combination of claim 1 wherein each said spindle comprises:

a rotatable body member supporting said peripheral drive surface;

a sleeve assembly for supporting a spool, which assembly is rotatably mounted on and movable relative to said body member; and

friction means disposed between said sleeve assembly and said body member to transfer rotational motion therebetween.

3. The combination of claim 1 wherein said means supporting each said spindle comprises:

a shaft coaxial to and joined to said spindle;

bracket means mounting said shaft for axial movement;

biasing means for urging said shaft to move axially in one direction; and

means engageable with said shaft for controlling the axial movement of said shaft relative to said bracket means.

4. The combination of claim 3 wherein said means engageable with said shaft comprises;

a pair of arms, each being pivoted about an axis transverse to the axis of each said spindle and having an angled member extending therefrom to a position below said bracket means and one end of the shaft supporting each spindle, one angled member being positioned within the path of said driven member andthe other angled member being positioned beyond the periphery of said driven member; and

actuating means for independently pivoting said arms about said transverse axis affording movement of said angled members and movement ofsaid spindles to place the spindles in driving engagement with said driven member.

5. The combination of claim 1 wherein said means supporting each said spindle supports each said spindle for independent axial movement from a first position to a second axially space position where it is engaged by said driven member and including drive means for rotating one of said spindles at a first rotational velocity when it is supported in its said first position.

6. The combination of claim 5 wherein said means for rotating said one spindle at a first rotational velocity includes a second drive surfaceon said driven member.

7. The combination of claim 1 including stationary support means for supporting a pair of spools on said pair of spindles against axial movement upon axial movement of either of said spindles.

8. A spindle assembly for use on a tape recording apparatus comprising:

a body member adapted to be rotatably mounted on a shaft. said body member comprising an axially extending hub, and a radial flange having an axially disposed face and means defining a peripheral frictional driving edge;

a first sleeve supported for free rotation on said hub and having a surface mating with said axially disposed face of said flange on said body member;

a second sleeve rotatably supported on said hub and joined for rotation with said first sleeve;

a spring positioned between said first and second sleeves urging said first sleeve toward said radial flange; and

a frictional pad secured to one of said axially disposed face and said mating surface to transfer rotational forces from said body member to said first and second sleeve. 9. A spindle assembly according to claim 8 wherein said second sleeve is formed with means for driving a spool.

10. In an apparatus for transporting a web, the combination a spool-supporting spindle having an axis and a peripheral drive surface;

means supporting said spindle for rotation about its axis and for axial movement from a first position to a second axially spaced position;

drive. means for rotating said spindle at a first rotational velocity when said spindle is supported in its said first position; and

a driven member having a drive surface disposed in axially aligned spaced relation to the drive surface ofsaid spindle for engaging said. peripheral drive surface of said spindle to drive said spindle at a second rotational velocity upon movement thereofto its said second position.

11. The combination of claim 10 wherein said drive means for rotating said spindle at a first rotational velocity includes a second drive surface on said driven member.

12. The combination of claim. 10 including stationary support means for supporting a spool on said spindle against axial movement upon axial movement of said spindle from said first position toward said second position.