US3140031A - Apparatus for feeding continuous webs - Google Patents

Description

July 7, 1964 c. J. FITCH APPARATUS FOR FEEDING commuous WEBS 2 Sheets-Sheet 1 Filed Jan. 25, 1962 FIG. //Vl//VTOR CLYDE J. FITCH 5) 14, 6. 01x9 ATTORNEY July 7, 1964 c. J. FITCH APPARATUS FOR FEEDING commuous WEBS 2 Sheets-Sheet 2 Filed Jan. 23, 1962 United States Patent 3,140,031 APPARATUS- FOR FEEDING CONTINUOUS. WEBS Clyde J. Fitch, Endicott, N.Y., assignor to International Business Machines Corporation, New York, N.Y., a corporation of New York Fiied Jan. 23, 1962, Ser. No. 168,036 7 Claims. (Cl. 226-109) This invention relates to apparatus for feeding continuous webs, and more particularly relates to apparatus for controlling concurrent intermittent feeding of. a plurality of continuous webs, such as tape, ribbons, or the like.

Recently, considerable effort has been directed toward developing high-speed matrix printers, such as of the wire-printer type, which print in a mosaic pattern. In these printers, it is customary to advance a paper tape and a carbon ribbon incrementally in converging paths past a print head, and print one character at a time while the tape and ribbon are stationary. Printing, of each character is eifected by driving appropriate ones of the individual solenoids for each printing element of the matrix. When the appropriate solenoids are de-energized, the print elements are retracted. This enables the tape and ribbon to be incrementally advanced preparatory to the printing of the next character.

In order for the incrementally advanced paper tape to be printed at high speeds, such as 100 characters per second, it is essential that the apparatus controlling the incrementing of the paper tape and carbon ribbon be of low inertia and capable of rapid operation. It is also desirable that the control apparatus be relatively simple, compact and inexpensive and that it be capable of use in other applications beside the printing field.

It is therefore one object of this invention to provide a compact, relatively simple, and inexpensive apparatus embodying a mechanism of low inertia for controlling feeding of continuous webs.

Another object is to provide an apparatusof the above type for controlling incremental feeding concurrently of a plurality of continuous webs of the same or different types.

Still anotherobject is to provide an apparatus of the above type embodying a manually operable mechanism to facilitate insertion of web material from a replacement source.

A further object is to provide an apparatus capable of feeding continuous webs without buckling the webs.

According to these objects, the apparatus comprises a single electro-magnet having an armature for controlling concurrent feeding of two separated continuous webs, such as a paper tape and a carbon ribbon which converge at a print station. A tape drive arm and a holder are laterally secured to the armature so as to be pivotable thereby. The paper tape passes between a guideway defined between a stationary guide and a laterally extending tape-overlying finger of the drive arm. This arm carries a thin flexible tape drive pawl or pusher that projects upwardly so as normally to pinch the tape against the under surface of the finger so the tape will be carried forward a predetermined distance when the magnet is de-energized. A flexible detent similar to the tape drive pusher contacts the upper surface of the tape and resiliently presses it against the guide to hold the tape against rear- 3,140,031 Patented July 7, 1964:

ice.

ward movement when the finger and pusher are movedrearward by energization of the magnet.

The carbon ribbonis fed-between the bite of a knurled drive; roll andta1pressure roll. When the magnet is deener-gized, theholden will advance a pusher into-jabbing engagement with a ratchet wheel to rotate it a given increment. The knurled roll is keyed to the same shaft as the ratchet wheel so that it will be rotated and thus feed the ribbon forward: a corresponding distance each time the magnet is de-energized. When the magnet is energized, the pusher is retracted from the ratchet wheel.

The finger of the tape drive pawl preferably has a rearwardly extending projection which overlies or overlaps a forwardly extending projection of the guide, the extent of such overlap being greatest while the magnet is energized. This prevents buckling of the tape during rearward motion of the finger and associated pusher upon energization of the magnet. Also, a toggle-type mechanism preferably is provided for normally biasing the pressure roll into contact with the knurled drive roll, but capable of holding these rolls biased a preselected distance apart to facilitate replacement of the ribbon.

The foregoing and" other objects, features and advantages-of the invention will be apparent from the following more particular description of a preferred embodiment thereof, as illustrated in the accompanying drawings, wherein:

FIG. 1 is a side elevation view of a web-feeding apparatus embodying the invention;

FIG. 2 is an isometric view, to enlarged scale, of a ribbon. feed mechanism shown in FIG. 1; and

FIG. 3 is a perspective view, to enlarged. scale, of a tape drive pawl and detent, also shown in FIG. 1.

As shown in FIG. 1', the web-feeding apparatus embodying the invention comprises an electro-magnet 10 including a coil 11 wound around one leg of a U-shaped core 12. The core 12 is laterally secured, such as by screws 13, to a fixed L-shaped member 14. The magnet has an armature 15 which is pivoted at- 16. A helical spring 17, which biases the armature away from the pole face of the core, seats against respective spring seats formed on the armature and at one end of a screw 18. This screw is adjustably positionable relative to the fixed member 14 to enable preadjustment of the bias force of spring 17, after which the screw preferably is locked in desired position by a lock nut 19'.

This. single magnet 10 controls concurrent incremental feeding of two continuous webs. in the manner now to be described. As illustrated, these web's are a paper tape T and a carbon ribbon R which are adapted to be fed in the direction of arrows 20, 21, respectively.

The tape T passes over a guide surface 22 provided by the flat upper surface of a lateral projection or flange forming part of an inverted L-shaped fixed element 23. As shown in FIGS. 1 and 3, tape drive arm 24 which preferably is of stamped metal, has a plurality of integrally formed fingers 25, 26, 27 which project transverselyof the feed path of the tape T. Finger 25 is substantially parallel to and disposed just above tape T; Whereas, fingers 26, 27 are below the tape and lie in a plane which intersects the feed path of the tape. A tape drive pawl or pusher is formed of flat spring steel and flexed. slightly in the direction of arrow 20 by being suitably connected to the inclined fingers 26, 27 so as to lie substantially in said plane. As illustrated in FIG. 3, this connection is effected by rivets 29 which are carried by the fingers 26, 27 and project into enlarged key-hole-like apertures in the pusher.

A central slot 30 provided in the upper end of pusher 28 straddles a projection 31 extending forwardly, in the direction of arrow 20, from the leftmost end of surface 22. This straddling permits the upper end of the pusher 28 to contact the bottom of tape T and normally frictionally pinch or squeeze the tape against the under surface 32 of finger 25. Finger 25 has a centrally disposed projection 33 that extends rearwardly and with lateral clearance between the side edges of a central slot 34 (FIG. 3) that is provided in the lower end of a detent 35, for reasons presently to be described.

Spaced from the guide surface 22 is a fixed element 36 which is preferably stamped to provide integrally formed fingers 37, 38. These fingers, like the fingers 26, 27 of the pusher 28, lie in a plane inclined at an angle to the feed path of tape T. The detent 35 has a configuration and composition identical with that of tape drive pusher 28 and is secured by rivets 29 to fingers 37, 38 so as to be flexed in the direction of arrow 20. This detent 35 holds the tape T against movement in a direction opposite to that of arrow 20. However, the detent 35 can flex to permit tape T to be fed in the direction of arrow 20 by the tape drive pusher 28 upon movement of the drive arm 24 to a limit position defined by contact with a stop 39. This stop is carried by a screw 40, which is adjustably positionable in a fixed element and preferably locked in position by a lock nut 41.

Referring now to FIGS. 1 and 2, the carbon ribbon R is fed through the bite of a pressure roll 42 and a knurled roll 43. Roll 42 is on the inked or carbon wax side of the ribbon. Therefore, it is formed of a material, such as polyethylene synthetic material, which does not pick up ink.

Pressure roll 42 is pivotally carried near one end or corner of a generally triangular support 44 that is rockably mounted on a pin 45. A helical toggle spring 46 has one end hooked around a fixed pin 47 and the other end wrapped around a pin 48 that is carried by the support 44. The support 44 has a manually engageable portion 49 to facilitate rocking of the support to either of two limit positions. In the normal position, in which the support 44 is shown in solid lines in FIG. 1, toggle spring 46 biases the pressure roll 42 into contact with drive roll 43. In the other limit position, denoted by dotted lines in FIG. 1, spring 46 biases the lower end of the support into contact with a stop surface 50 to hold the pressure roll 42 a preselected distance away from roll 43. This toggle action permits the rolls 42, 43 to be held apart mechanically, thus freeing both hands of the operator to facilitate insertion of a replacement ribbon R between the rolls 42, 43.

Rotation of drive roll 43 and hence the feeding of ribbon R is effected by a pusher 51 (FIG. 1) which may be rectangular in shape and press fit into an inclined slot 52 provided in an offset or widened portion of a pusher holder 53. To prevent wear, the upper or read edge of the pusher 51 preferably abuts the downturned terminal part of an inesrt 54.

It is to be noted that the holder 53 is secured, such as by rivets 55, to the armature 15 so as to be rockable thereby. The tape drive arm 24 is welded or brazed to the armature 15.

Summary of Operation Assume initially that the paper tape T is threaded into the guideway between surface 22 and detent 35 and the overlying finger 25 of tape drive arm 24 and pusher 28; that the ribbon R has been positioned between rolls 42, 43, in the manner above described, by rocking the support 44, and helped by the toggle action of spring 46; and that electro-magnet is energized. Under these assumed conditions, the various components will be in respective positions in which they are shown in FIG. 1.

When coil 11 is de-energized, spring 17 will rock armature 15 counterclockwise and thus correspondingly rock the tape drive arm 24 and holder 53 until said armature strikes stop 39. During this arcuate movement of arm 24, tape T will be held pinched against the under surface 32 of finger 25 by the pusher 28; and hence the tape will be advanced leftward an increment corresponding to the preadjusted degree of arcuate movement of arm 24. The tape can move leftward because detent 35 yields under the pulling force exerted on the tape by the pusher 23.

Meanwhile, as holder 53 moves counterclockwise, it carries pusher 51 into jabbing, substantially tangential contact with one of the teeth of a ratchet wheel 56 for rotating said wheel a predetermined increment clockwise as viewed in FIG. 1. As ratchet wheel 56 thus moves clockwise, it will, through a shaft 57, rotate the drive roll 43 clockwise a corresponding increment for causing the carbon R to be advanced a corresponding distance leftward through the bite of rolls 42, 43.

When coil 11 is energized, armature 15 will be attracted toward the pole face of core 12 and store power in spring 17. As illustrated, the energized position of the armature is defined by contact with a rotatably adjustable eccentric stop 58. As the armature rocks clockwise about pivot 16, it carries holder 53 and thereby retracts pusher 51 from contact with the ratchet wheel 56. Meanwhile, tape drive arm 24 will be pulled clockwise by armature 15, for thereby flexing and dragging the upper end of pusher 28 rightward along the under side of tape T while the tape is being held stationary by detent 35.

As the overlying finger 25 of arm 24 moves rearwardly over the top of the then stationary tape T, buckling of the tape will be prevented. More specifically, as arm 24 and hence the overlying rearwardly extending projection 33 move rearward over the tape, the tape will be supported on the forwardly extending stationary projection 31 provided by element 23 (see FIG. 3). Thus, the tape is supported over a substantial longitudinal distance as a result of the overlapping of these projections 33, 31; and it is this overlapping which prevents the buckling. By way of contrast, if no such projections were provided, and the rear edge of finger 25 and forward edge of surface 22 were straight in a direction transverse to the tape T, the tape would be gripped strongly enough between the bite of finger 25 and pusher 28 to buckle the tape between two points: one being at said bite, and the other being at the forward transverse edge of the detent 35. In such event, the degree of such buckling would, of course, depend upon the amplitude of rockable movement of arm 24.

It is to be noted that the central slot 34 in the lower end of detent 35 permits the rearward projection 33 of the tape drive arm 24 to move rearwardly of the leading edge of detent 35 to the position in which it substantially overlaps the forwardly extending projection 31 of surface 22, as shown in FIGS. 1 and 3.

It should also be noted that, unlike previously proposed arrangements, the elements at both sides of the tape (namely, the finger 25 and pusher 28) oscillate in unison. This is highly desirable because by gripping and moving forward with the tape, no frictional forces retarding the tape motion are developed at this point. On the other hand, if the finger 25 were stationary and only the pusher 28 oscillated, it is clear that the finger would impose a drag that would impede forward motion of the tape.

While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that changes in form and details may be made therein without departing from the spirit and scope of the invention.

5, What is claimed is: 1. Apparatus'for controlling concurrent feeding of two webs, comprising:

a rockable member providing a finger extending generally atrightangles to the plane of movement of such member,

a flexible pusher carried by said member and' normally biased toward said, finger to frictionally grip opposite sides of one, of. the webs therebetween to move said one, web forward a, selectedincrement during rocking of said member one way a predetermined amount,

means including adetentfor pressing said one web against a stationary surface to prevent rearward movement of said web during rocking of said member the opposite way,

said pusher being yieldable to permit relaxation of said grip by said pusher during such rocking of said member said opposite way, and said detent being yieldable to permit such forward movement of said one web,

two rolls providing a bite through which the other web is feedable,

another pusher for operatively effecting rotation of one of said rolls a selected amount for advancing said other web a corresponding increment, and

a single actuator operatively connected to said pushers for concurrently controlling their operation and thereby concurrent movement of both webs, said finger and stationary surface each having adjacent portions which overlap during rocking of said member said opposite way, thereby to minimize buckling of such web as it is held against movement by the detent-including means.

2. In an apparatus for controlling feeding of a continuous web, the combination of:

a drive arm rockable between predetermined limit positions,

a pusher carried by said arm for normally pinching the flat dimension of the web against a co -operating surface of said arm extending generally at right angles to the plane of movement of such arm,

means providing a fixed surface, and

a detent normally pinching the web against said fixed surface,

said pusher and detent being flexible and disposed at angles to the web to permit the detent to yield while the web is advanced one way by rocking of the arm and pusher concurrently in one direction, and permit the pusher to yield and move relative to the web as the pusher and arm rock concurrently in the opposite direction and the detent prevents movement of the web the opposite way,

the co-operating surface of the arm and fixed-surfaceproviding means each carrying respective projections which are disposed at opposite sides of the flat dimension of the web and extend generally toward each other in an overlapping relation to present irregular facing ends on said arm and surface-providing means to prevent buckling of the web during movement of said pusher and arm in said opposite direction.

3. The combination according to claim 2, wherein:

the detent straddles the path of movement of the projection on said arm and normally clamps the web between said detent and the fixed surface at a point rearward of the projection provided thereon, and

during movement of said arm in said opposite direction the projection thereon will extend rearward of such point.

4. Apparatus for feeding a web, comprising means including two laterally offset members providing a channel through which the web is feedable,

at least one of the members having a main portion from which a projection extends toward the other member and is disposed to overlap such other member upon movement of said members relatively towardeach other,

a pusher element forclamping the web against a particular one of the members as the latter. moves relatively away from the remaining member. to cause advancement of the web, and

a, detent element for clamping the web against said remaining member to prevent retrogression of the web as said particular one. member moves relatively toward said remaining member,

the projection on each member provided therewith being of such length and configuration relative to the particular element associated with the other of the two members as to extend up to and beyond the place where the said particular element contacts the web, thereby to prevent buckling of the web during movement of said members relatively toward each other.

5. Apparatus for feeding a web, comprising means including a movable member and a laterally offset co-operating member providing a channel through which the web is feedable,

said members each having respective projections that extend toward each other from respective main portions and which projections are disposed to overlie each other upon movement of the members relatively toward each other,

a pusher element for clamping the web against the main portion of the movable member as the latter moves one way to cause advancement of the web, and

a detent element for clamping the web against the main portion of the co-operating member to prevent retrogression of the web as the movable member moves the opposite way during a return stroke,

each such element being so configured as to permit the projection on the member associated with the other of the elements to move relatively past the place where such element effectively clamps the web against the main portion of the associated member, thereby to prevent buckling of the web during such return stroke of the movable member while the web is held stationary by the detent element.

6. Apparatus for feeding a web, comprising a member movable back and forth between predetermined positions and providing a surface disposed generally at right angles to the plane of movement of such member,

a flexible pusher carried by said member and biased toward said surface to clamp said web therebetween to move said web forward a selected increment during movement of said member one way,

means providing a stationary surface generally parallel to the first-mentioned surface, and

a flexible detent for pressing said web against said stationary surface to prevent retrogression of said web during movement of said member the opposite way,

the pusher being yieldable to permit it to move relative to the web during movement of said member said opposite way, and the detent being yieldable to permit such forward movement of said web,

each of said surfaces having adjacent portions which overlap during movement of said member said opposite way, thereby to confine the web for a substantial portion of its length between said surfaces to minimize bucklng of the web as it is held against movement by the detent.

7. In an apparatus for feeding a web, the combination means including a movable member and pusher for clamping the opposite sides of the fiat dimension of the web during movement of said member in one direction, for advancing the web one way, and means including another member and detent for clamping said opposite sides of the web upon movement of said member in the opposite direction, for preventing movement of the web the opposite way,

said pusher and detent being flexible and inclined generally said one way to respectively permit the pusher to be moved said opposite way relative to the web and also permit the web to be moved said one way relative to said detent,

said movable member and other member having projections which are moved into overlying relationship with each other when said movable member moves in said opposite direction, thereby to prevent buckling of the web while it is held against movement said opposite way by said detent.

References Cited in the file of this patent UNITED STATES PATENTS Greenbaum et al Apr. 9, 1929 Rosenthal Aug. 9, 1932 Potts Oct. 12, 1948 Cooper et a1 Jan. 31, 1956 Garwood Apr. 30, 1957 Schechter July 1, 1958 Trimble Dec. 16, 1958 Turner et a1 July 17, 1962

Claims (1)

1. 7. IN AN APPARATUS FOR FEEDING A WEB, THE COMBINATION OF MEANS INCLUDING A MOVABLE MEMBER AND PUSHER FOR CLAMPING THE OPPOSITE SIDES OF THE FLAT DIMENSION OF THE WEB DURING MOVEMENT OF SAID MEMBER IN ONE DIRECTION, FOR ADVANCING THE WEB ONE WAY, AND MEANS INCLUDING ANOTHER MEMBER AND DETENT FOR CLAMPING SAID OPPOSITE SIDES OF THE WEB UPON MOVEMENT OF SAID MEMBER IN THE OPPOSITE DIRECTION, FOR PREVENTING MOVEMENT OF THE WEB THE OPPOSITE WAY, SAID PUSHER AND DETENT BEING FLEXIBLE AND INCLINED GENERALLY SAID ONE WAY TO RESPECTIVELY PERMIT THE PUSHER TO BE MOVED SAID OPPOSITE WAY RELATIVE TO THE WEB AND ALSO PERMIT THE WEB TO BE MOVED SAID ONE WAY RELATIVE TO SAID DETENT, SAID MOVABLE MEMBER AND OTHER MEMBER HAVING PROJECTIONS WHICH ARE MOVED INTO OVERLYING RELATIONSHIP WITH EACH OTHER WHEN SAID MOVABLE MEMBER MOVES IN SAID OPPOSITE DIRECTION, THEREBY TO PREVENT BUCKLING OF THE WEB WHILE IT IS HELD AGAINST MOVEMENT SAID OPPOSITE WAY BY SAID DETENT.

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