Abstract: A device for the feeding or advancement of an edgeperforated paper web (1) in a dot-matrix printer or the like includes a pair of drive belts (3) transversely spaced apart proximate opposite transverse edges of the web, each belt carrying on its upper surface (6) a series of pins (7) for releasable engagement with the edge-disposed web perforations (11). To provide an increase in friction between the paper web (1) and the drive belts (3) during transport of the web, and thereby assure enhanced accuracy and precision in operatively advancing the web, a plurality of upstanding or outwardly-protruding projections (17, 17a, 17b, 17c) are defined on the upper belt surface (6). These projections are located at least in the flat sections (16) of the belt between adjacently or successively-disposed ones of the pins (7) and, in another form of the invention, additionally at and coincident with the locations of the pins (7) which interrupt the transversely-oriented projections.

Abstract: A device for the transport of multilayer, edge-perforated imprint-receiving substrates (8) takes into consideration a curve-shaped transport path (9), wherein a thrust tractor pair (5) is disposed in front and ahead of a substrate support (2), as seen in transport direction (10). Several friction roller pairs are following to the thrust tractor pair (5). In each case, a pulling force is transferrable by way of at least one friction roller. The multilayer imprint-receiving substrate (8) rests with its rear layer (8a) on the substrate support (2). A tearing of the edge perforations of the imprint-receiving substrate (8) as well as belly and bulge formations of one of the two layers (8a, 8b) is avoided by furnishing the push tractor (5) with a braking element (19) for the front layer (8b). A following first friction roller pair (11) rests with a driven friction roller (11a) at the front layer (8b).

Abstract: An integral frame type paper feeder in which perforated paper is fed by a pin-carrying feed belt set in a main frame by a driving sprocket. The paper feeder has a pair of sub-frames for assembling the feed belt and driving sprocket in a sub-assembly, and a main frame consisting of a pair of opposed side plates spaced from each other at a predetermined distance, and to which the sub-frames are fixed, and an upper plate the upper surface of which constitutes a paper feed surface. The upper plate has a feed belt moving bore which extends in the direction in which the perforated paper is fed, and which causes the portion of the feed belt on which the perforated paper is being fed to be aligned with the paper feed surface. The two sub-frames, and the feed belt and the driving sprocket are combined with the sub-frames into a driving assembly, and this is fitted between the side plates of the main frame.

Abstract: A perforated paper feed mechanism such as a tractor has an optical system for detecting the presence of the form and particularly the motion of the form and utilizes a reflector which may be mounted on the lid of the tractor at one end of the tractor (where the paper enters or leaves the tractor). The optical system may be implemented by a prism which folds the path of light from a light source (an LED) to a photo detector (a photo-transistor) the path is aligned with the perforations in the paper. Since the perforations are spaced, the photo transistor provides a train of pulses as the paper is fed by the tractor. A pulse detector responds to the presence or absence of pulses within a given period of time comparable to the time when perforations are fed past the optical path. An output from the detector thus indicates whether the paper is in motion and is being fed by the tractor. Failure to receive pulses indicates either the absence of paper (paper out) or a jam in the feed.

Abstract: A feed belt driving sprocket has a body molded of an elastic material. Two side faces of an inner circumferential portion of the sprocket body, except an outer circumferential portion formed with teeth, are formed with round fitting recesses concentric with an axial hole therein such that the inner circumferential portion of the sprocket body is thinner than the outer circumferential portion. The axial hole formed at the center of the sprocket body has small protrusions on its inner circumferential faces. Notched holes are provided in the sprocket body for facilitating elastic deformation of portions of the sprocket body. If a drive shaft is fitted into the axial hole of the sprocket body, the portions of the sprocket body near the axial hole are partially elastically deformed. The clearance between the drive shaft and the axial hole of the sprocket body is thus eliminated and the sprocket is immovably fitted onto the drive shaft.

Abstract: An apparatus for feeding a sewing machine with a textile fabric with opposite side hems. The sewing machine has a needle assembly and a bobbin assembly which are vertically aligned with each other to sew a textile fabric placed at a position between the needle and bobbin assemblies. The feeding apparatus is designed to set and withdraw the fabric into and from said position.

Abstract: A sheet feeder for feeding continuous printing paper having sprocket holes includes a pair of frames, a drive gear and a guide gear interposed therebetween, and a pin tractor belt extending between the drive gear and the guide gear. The drive gear and the guide gear respectively have flanges at the both ends thereof for tightly holding the pin tractor belt. A guide roller is interposed between the drive gear and the guide gear and is rotatably supported by one of the frames. The pin tractor belt smoothly travels over the guide roller. The pin tractor belt has a plurality of pins provided at an upper surface thereof to be engaged with sprocket holes of continuous printing paper for feeding the continuous printing paper. Inasmuch as the upper surface of the pin tractor belt projects above the upper surfaces of the frames, the continuous printing paper is fed without contacting the frames.

Abstract: A paper tension adjusting device in which one of the tractors with feeding pins changing feeding apertures in the paper is movable widthwise to adjust widthwise paper tension. The desired tension is determined from paper thickness which is in turn determined from the hammer flight time. Lengthwise tension is adjusted by adjusting paper clampers separated from the tractors. The tension is both widthwise and lengthwise directions is determined by optically sensing the positions of the feeding pin with respect to the aperture in which that pin is engaged.

Abstract: A tractor for feeding perforated paper forms as in a printer, to and around a platen where a print head impresses characters or other symbols on the paper. The tractor has an endless belt with pins engageable in the paper before, during and after engagement with a drive sprocket which drives the belt in such a manner that the load on the paper is polarized to one side of the drive sprocket, preferably the side between the drive sprocket and the platen.

Abstract: A printer has a main pin tractor unit fixedly provided interiorly of a printer housing and an auxiliary pin tractor unit detachably mounted on the printer. The auxiliary pin tractor unit is mounted in a position immediately above the main pin tractor unit so that when the axuiliary pin tractor unit is detached from the printer, the main pin tractor unit is exposed to allow a continuous print sheet to be readily loaded on the main pin tractor unit. To selectively drive the main and the auxiliary pin tractor units with a single motor, a changeover mechanism is provided.

Abstract: A feed mechanism for transporting paper has an endless band with transport pins for insertion into the perforations in circular perforations in the paper. The feed pins are part of drive elements attached through perforations in an endless flexible band to gear teeth which are engaged by grooves in a drive pulley. The transport pins have a cap portion on top of a base portion. The cap portion is tapered in the shape of a circular involute and extends from the top of the truncated circular conical base portion. The perforations in the band have the shape of an ellipse with the major axis thereof aligned in the direction of movement of the band. The band can be either thin flexible steel or polymer and the pin portion and gear portion of the drive elements can be integral and molded from an elastomer material through the elliptical perforations in the band.

Abstract: An improved lid for a forms feed tractor, which feeds successive interconnected sheets of paper having edge perforations (feedholes), the sheets having forms printed thereon or being blank, in printers, copiers and the like is provided with an improved lid mechanism having an extension outboard of the tractor and over the form. A transparent or translucent window section in this extension is provided with markings which are seen when the lid is pivoted down and closed so as to capture the form. Then the form can be moved so that the edge of each sheet or certain markings on the form are in proper alignment in the printer or copier. Then when printing occurs or when copying onto the form occurs, the printing will be located in line with other material on the form or properly spaced from the top edge of each sheet.

Abstract: A paper feeder has a pair of spaced opposed side frames, a driving sprocket having external teeth on the outer circumferential surface thereof and a supporting shaft on which the driving sprocket is mounted and rotably mounted between the two side frames, and an endless feed belt having a portion around the driving sprocket and having feed pins on the outer circumferential surface and engageable with perforations in perforated paper, and having internal teeth on the inner circumferential surface thereof meshed with the external teeth for being turned by the driving sprocket.

Abstract: A paper transporting tractor for transporting paper provided with sprocket holes at an equally spaced interval along either side thereof includes a first endless belt having a plurality of sprockets at its outer peripheral surface and a serrated portion at its inner peripheral surface, a driving gear which is in mesh with the serrated portion of the belt thereby causing the belt to move either forward or backward, an end guide portion provided as spaced apart from the driving gear to provide the first endless belt as extended between the gear and the end guide portion and a second endless belt of thin film provided around the end guide portion as sandwiched between the first endless belt and the end guide portion at least partly thereby allowing to substantially decrease the friction between the first endless belt and the end guide portion.

Abstract: An improved lid mechanism for a web feed devices such as tractors for feeding perforated paper webs in printers, copiers and the like, wherein pins on which the lid is pivotally mounted for movement between open and closed position are unloaded (do not have any force or bias applied thereto) when the lid is in its open and closed position. The lid, when closed, covers the paper and is then spaced by a gap from the surface of a frame along which the paper is fed by a pin drive such as a belt having pins which extend into perforations of the paper. A depending leg of the lid has a block with surfaces disposed at an angled to each other. These surfaces extend from a corner of the block. One of these surfaces is preferably perpendicular to the surface of the lid which defines the gap. The other of these surfaces defines the position of the lid in its open position.

Abstract: In a printer for use with a continuous form, a tractor drive shaft and a tractor guide shaft are mounted to a tractor frame of a bi-directional form feeder unit in parallel relation to each other. A pair of tractors mounted on both the shafts are movable therealong, but can be fixed to a shaft body of the guide shaft at respective desired positions. Opposite axial ends of the drive shaft are received respectively in a pair of elongated slots whose longitudinal axes extend substantially perpendicularly to a platen. One axial end of the drive shaft is drivingly connected to a drive unit. A pair of support shaft sections extend respectively from opposite axial end faces of the shaft body and are supported by the tractor frame. An axis of the shaft body extends in eccentric relation to an axis common to the support shaft sections. The shaft body is angularly movable about its axis relatively to the tractors.

Abstract: A tractor feed mechanism for feeding print forms comprises a continuous flexible pin belt wrapped around a pair of drive pulleys rotatably supported by a tractor body. Pins projecting from the flexible belt engage the forms via perforation in the forms. A door pivotally connected to the tractor body and is rotatable between an open condition in which paper can be placed on or removed from the pins and a closed position in which the forms can be restrained from becoming disengaged from the pins during feeding by the pin belt. A cam rotatable with the door and a spring is operable therewith produce a first restraining force on the door in its closed position which allows the door to be lifted a predetermined amount by the forms during feeding by the pin belt to accommodate variations in the thickness of the forms caused by buckling or folds.

Abstract: A justification system for use in a printer employing a continuous recording form. The justification system comprises a timing pulse signal generating system which generates timing pulses in synchronism with the traveling of sprocket holes of the continuous recording form. The timing pulses signals for commencing the printing on each printing segment defined on the continuous recording form and the timing for stopping the advancement of the continuous recording form are controlled based upon the above timing pulse signals. With this control, printing can be executed with a correct positional relationship with rules on each printing segment, even if the continuous recording form is set in the printer with a slight misalignment in the direction of the travel path of the continuous recording form or if the form itself has expanded or contracted in its longitudinal direction due to the effect of humidity.

Abstract: A tractor drive for feeding continuous paper in an office machine has a drive shaft provided with an axially extending groove; a tractor housing; a drive wheel rotatably supported in the tractor housing; a transport member connected to the drive wheel to be driven thereby and arranged to project into marginal perforations of the paper for transmitting a feeding force thereto; a bearing sleeve affixed to the drive wheel and coaxially mounted on the drive shaft; a feather key carried by the bearing sleeve; and an actuating member operatively connected to the feather key. The actuating member has a clamping position in which it presses the feather key into a clamping contact with the bottom of the drive shaft groove, whereby the tractor (formed of the tractor housing, the drive wheel, the transport member and the bearing sleeve) is axially immobilized relative to the drive shaft.

Abstract: A paper feeder for tractor-feed printers. A frame movably mounts an endless belt having a plurality of feed pins. A cover is pivotably mounted to the frame and may be pivoted between open and closed positions. In the closed position a lower surface of the cover faces the endless belt. An elastically deformable holding member extends from the lower surface of the cover to urge the paper into engagement with the feed pins.

Abstract: A transport device for edge-perforated recording support material (1) comprises two casing parts (2, 6) disposed at a distance relative to the perforation edges (1a) for drivable endless pin belts (5) with respectively a guide flap (4) for the recording support material (1), where the casing in each case comprises two casing parts (2, 6) disposed next to one another, and where the guide flap (4) is tiltably disposed on a first casing part (2), where inner and outer guide ribs (7, 10, 11) for the pin belt (5) are provided, where aligned disposed means for the detachable attachment of the two casing parts (2, 6) are provided aligned at the first and the second casing parts (2, 6) where at least the inner guide ribs (7) form a rest contact surface (6a) for the second casing part (6).

Abstract: A paper handling system for a printer or copier has a forms feed tractor employing a sliding sprocket assembly and idler sprocket. The idler sprocket is mounted on the sliding sprocket assembly providing for adjusting the tension on the belt. The sliding sprocket assembly also has an inclined ramp thus providing a symmetric belt path.

Abstract: A strip provided adjacent the edges thereof with perforations is driven forwards during a printing operation by the cooperating printing and counter-pressure cylinders of an offset mechanism, and by two pairs of pin tractors, pins of which enter the somewhat larger perforations. When the cylinders release the strip, same is moved backwards by the pin tractors over a distance equal to the difference between the forward displacement and the length of a form. To position the strip before a new printing operation, those pins going through the perforations of the pin tractors are moved a little forwards until they lie anew frontwards in the perforations.

Abstract: A device for a paper transport in an office machine, in particular in a matrix printer, presupposes the presence of side plates (1, 2), wherein a print-support surface (7) is supported and, in addition, a friction drive including a roller pair for individual sheets (9) to be transported or, respectively, endless webs (10) without edge perforation, and tractors (13) provided in pairs, which operate in push and pull operation.

Abstract: A method and associated apparatus for quickly and accurately advancing paper between the platen and printing mechanism on a line-by-line basis in a high speed printer for printing lines of text including a platen and a printing mechanism disposed adjacent the platen.

Abstract: A web loading and feeding system comprises an elongated web and a web loading and feeding machine. The web is fed longitudinally of itself through the machine by a pair of drive sprockets having pins which cooperate with holes in side edge portion of the web. The hole arrangement in the web and the pin arrangement on the sprockets readily enable a machine operator to visually determine how to properly load the web onto the sprockets.

Abstract: In an image fixing apparatus, a fixing roll unit is arranged in a predetermined path along which a continuous form travels, for applying pressure and/or heat to an image on the continuous form to fix the image thereonto. An endless belt member is arranged upstream of the fixing roll unit with reference to a transport direction in which the continuous form travels along the predetermined path. The endless belt member has provided thereon a plurality of projections arranged in spaced relation to each other along an outer periphery of the endless belt member. The projections are engageable with sprocket holes formed in the continuous form along opposite side edges thereof. The endless belt member is capable of running in the transport direction while applying a predetermined back-tension to the continuous form traveling toward the fixing roll unit along the predetermined path.

Abstract: A web feed tractor mechanism 10 is illustrated in the drawings for moving a web material in a longitudinal direction in which the web material has perforations along edge sections 16 and 18 for enabling precision movement of the web particularly for use in computer output printing. The web tractor mechanism has two parallel tractors 34 and 36 that support and drive tractor drive belts 54 and 56. The belts 54 and 56 have drive pins 70 and 72 respectively for engaging the perforations along the opposite side edge section 16 and 18. Preferably the pins 70 have a reduced cross-section that is both longitudinally and laterally symmetrical, with lateral and longitudinal dimensions that are substantially equal. The surfaces of the pins 70 engage the inside edge of the perforations and drive the web forward while preventing lateral movement of the edge section 16 to provide lateral stability.

Abstract: An endless belt used in a paper feeding apparatus for feeding paper to a printer in a computer or the like, the paper having feed holes formed at equal intervals in both side portions thereof. A large number of feed pins to be inserted into the above feed holes are formed on the outer peripheral surface of the endless belt. The feed pins are arranged so that there is repeated a pattern of interaxial spacings of P+a/2, P+a/2, P-a/2 and P-a/2, in which P is the distance between the centers of feed holes formed in the paper and a is a mean value of differences between feed pin outside diameters of the portions in abutment with edge portions of the feed holes and the feed hole diameter. Alternatively, the feed pins may be arranged at interaxial spacing between adjacent feed pins of P+a and P-a alternately.

Abstract: For a computer printer having a paper feeder designed to engage a continuous perforated paper having a series of prepunched holes on the left and right marginal strips, a vacuum attachment is disclosed for keeping clean the interior of the computer printer from dust, paper perforations, paper punch waste materials, or other debris produced during printing operations, comprising vacuum means, nozzle means operably connected to said vacuum means, and means for amounting the nozzle means adjacent the paper feeder of the computer printer.

Abstract: A tractor for feeding perforated paper has an endless belt of flexible material having pins and teeth extending in opposite directions from said belt. The belt has more rigid sections corresponding to the locations of the teeth between flexible web sections. A pulley is provided which has curved sections and grooves for receiving the teeth of the belt. The curved sections comprise an arc with ends having points of tangency with planes of straight sections of the belt extending across the grooves. The curved sections may comprise a composite arc having end arc sections with points of tangency with the planes of the straight sections of the belt and a center arc section having points of tangency with the end arc sections. The curved sections may also be an arc which has a continuously increasing radius of curvature from the points of tangency with the planes of the straight sections of the belt to a center line between the grooves.

Abstract: A paper feed apparatus for a printer, having a belt type paper feed mechanism and a feed wheel both mounted on a frame. The belt type paper feed mechanism is of a construction in which a driving sprocket and two driven sprockets are arranged so that the respective rotational axes are positioned at the angles of a triangle, and in these positions the three sprockets are rotatably supported by the frame, and an endless belt is entrained about those sprockets. The endless belt has feed pins erected in a row at predetermined intervals on its outer peripheral surface. The feed wheel is supported by the frame rotatably about a rotational axis parallel to that of the driving sprocket in a position close to the same sprocket, and it has feed pins radially erected in a circumferential row at predetermined intervals on its outer peripheral surface.

Abstract: A tractor is provided with an endless belt which travels in a triangular path and a drive shaft located well below the level of the paper path. The tractor body has both an inner and outer body portion, each of which contains a journal bearing for support on the support shaft. An adjustable torsion spring lock is provided on the outer body portion and surrounds the support shaft to allow for easy locking adjustment of the axial location of the tractor on the support shaft. A front and rear closeable panel are provided along the document feed path. Only the front panel need be opened during feeding while both front and rear panels may be opened to clear the feed path during advancement jam. Two mirror image features are provided at the entrance of the feed path on either body portion such as to cover document pins located on the belt path and thereby decrease likelihood of injury to an operator during feeding operations.

Abstract: The paper feeder incudes an upstream friction roller pair for single sheet feeding, a pushing tractor for endless sheet feeding, and a common downstream (behind the platen) friction roller pair. Each pair has one roller mounted on a pivot lever and the two levers linkedly held in a spring biased linkage such that consistently the downstream roller pair exert a smaller friction force while rotating at a higher speed.

Abstract: A pin tractor assembly for feeding a medium having feed perforations such that the perforations engage drive pins provided on an outer surface of a rotating endless belt which engages a pair of wheels rotatably supported between two spaced-apart frames. The two spaced-apart frames are connected to each other by a connecting portion, into an integral tractor body having a slot portion which accommodates the pair of wheels and the endless belt. The assembly has a device for inhibiting radial movement of the pair of wheels positioned in the slot portion of the tractor body.

Abstract: A web feed tractor includes an endless feed belt having feed pins projecting from the outer surface thereof, and a pair of side frames disposed along the opposite edges of the feed belt. A driving pulley is rotatably supported between one ends of the side frames and is adapted to engage the inner surface of the arcuate driving portion of the feed belt so as to drive the feed belt. A belt guide is provided between the side frames and has a guide surface adapted to guide the inner surface of the arcuate driven portion and the upper and lower reaches of the feed belt. The guide surface is positioned in longitudinally aligned relation to the feed pins of the feed belt and has a width substantially equal to the diameter of the feed pin.

Abstract: A sheet feed tractor of the type used in printers for automatically advancing paper and the like has a recess in one surface of the chassis about the passage for the support shaft and axially extending, resiliently deflectable fingers in the recess and through which the support shaft will pass. The fingers are disposed in substantially alignment with the drive belt and are deflected inwardly by a rotatable clamping member disposed thereabout to effect clamping action on the support shaft substantially in alignment with the drive belt. This orientation of the clamping action precludes inadvertent movement of the tractor on the support shaft during clamping of the tractor thereon and also eliminates undesirable torque on the tractor when the tractor is operating by essentially eliminating any moment arm between the clamped area and the center line of the drive belt.

Abstract: A feed mechanism for a printer having a door with hinge elements connected by hinge pins to the tractor body so as to be rotatable between first and second position. The hinge elements have rotary cams with convex and planar surfaces. A single flat steel spring is simply supported between its ends by a platform. The spring is held in flexed condition in a continuous bend by the platform and the cams of the hinge elements. The platform has coplanar support edges for simply supporting the spring. Alignment and centering means on the platform maintain the horizontal axis of the spring aligned with the common axis of the hinge pins and centered between the cams.

Abstract: A pin belt type paper tractor comprises a drive shaft rotatively driven at the time of feeding a recording paper, a belt driving wheel fitted slidably in the axial direction on the drive shaft for the rotation therewith, and a chassis body for pinching the belt driving wheel from the opposite sides thereof. The chassis is movable in the widthwise direction of a recording paper and is in engagement slidably at its peripheral portion with a fixed support frame having a length not less than the paper width. A rotary member is rotatably supported by the chassis body and an endless belt is engaged between and around the belt driving wheel and rotary member. The endless belt is provided on its outer peripheral surface with a plurality of pins brought into engagement with the perforations of the recording paper. A paper holding cover is pivotably attached to the chassis body in open and close directions.

Abstract: A tractor for driving web material has an endless belt which travels about spaced apart drive and idler sprockets, one of which is an entrance sprocket and the other an exit sprocket. The idler sprocket is journalled in a support member which is movable on the tractor chassis by an adjusting member to vary the spacing between the sprockets and thereby adjust the tension in the belt. The belt carries the paper over a rectilinear path between the sprockets and the chassis has upper surfaces along that path which rise prior to the exit sprocket to lift the paper on the drive pins on the belt and provide a ramp surface clearance to effect clearance of the drive pins in the perforations of the paper so that they rotate downwardly without excessive wear and friction between the web around the perforations and the surface of the pins.

Abstract: A tractor is provided with an endless belt which travels in a triangular path and a drive shaft located well below the level of the paper path. The tractor body has both an inner and outer body portion, each of which contains a journal bearing for support on the support shaft. An adjustable torsion spring lock is provided on the outer body portion and surrounds the support shaft to allow for easy locking adjustment of the axial location of the tractor on the support shaft. A front and rear closeable panel are provided along the document feed path. Only the front panel need be opened during feeding while both front and rear panels may be opened to clear the feed path during advancement jam. Two mirror image features are provided at the entrance of the feed path on either body portion such as to cover document pins located on the belt path and thereby decrease likelihood of injury to an operator during feeding operations.

Abstract: A feed mechanism for moving a web is disclosed. It includes a means for engaging the web that has a plurality of uniformly spaced drive pins for extending through and engaging web perforations. It also includes a means for guiding the web onto the drive pins, such as a door, and it includes a guiding surface that extends below the upper end of the pins. The guiding surface includes a static protrusion that extends below the guiding surface and urges the web and its associated perforation down onto the drive pin in that portion of the tractor where the drive pins are inserted into the web perforations.

Abstract: A pin tractor for feeding blank paper for use in various printers, typewriters, etc. which are used as output devices for electronic computers, especially for personal computers. A belt carrying pins is driven to turn by a toothed driving pulley provided at a frame comprising only one member. The toothed driving pulley is supported to the frame only at one end portion thereof and the other end portion is a flange exposed outwardly. A positioning mark is provided at the exposed surface of the other end portion of the pulley.

Abstract: A paper feeding tractor including a frame formed by a pair of said frames; a driving sprocket rotatably supported between both side frames at a first end portion of the frame; an endless belt adapted to be driven by the driving sprocket; a pair of first supporting rollers located at a second end portion of the frame and arcuate guiding members projecting from the opposite inner surfaces of the side frames at the second end portion for supporting said endless belt in a loop, whereby the endless belt is arcuately supported by the first supporting rollers and the arcuate guiding members; and a second supporting roller rotatably supported between both side frames at a longitudinal position between the driving sprocket and the first supporting rollers to support the inner peripheral surface of the end belt.

Abstract: A paper feeding mechanism wherein tractors which convey a sheet of paper by means of belts when a driven shaft connected to a drive gear is rotated are supported swingable round a support shaft to move from their closed position to their open position and vice versa, characterized by a stopper member having those teeth which are selectively engaged with the drive gear to stop the rotation of the drive gear, and by a drive member for driving the stopper member to engage its teeth with the drive gear only when the tractors are under their open position. The free running of the belts can be this prevented when the tractors are under their open state, thereby allowing the sheet of paper to be stably mounted.

Abstract: A web feed tractor which comprises a frame, a drive gear rotatably mounted in the frame, a cylindrical shaft fastening member mounted on the frame with a portion thereof protruding from the frame, an endless toothed timing belt trained about the frame and drive gear, a cover plate assembly peripherally surrounding the endless belt in peripherally spaced relationship to the belt to define a track of a web to be fed, a web support or guide member positioned adjacent to the endless belt in side by side relationship, a lock ring rotatably mounted on the protruding portion of the shaft fastening member and a switch mechanism positioned in the track of the web so as to be operated by the web as the web passes through the track.

Abstract: A web feed tractor having a pair of side frames, a driving pulley and at least one idler pulley rotatably supported between the side frames at spaced intervals, an endless feed belt trained around the driving and idler pulleys, at least one support roller rotatably disposed between the side frames and adapted to support the inner surface of the upper reach of the feed belt, and restraining means disposed between the driving and idler pulleys and the feed belt and adapted to restrain lateral meandering of the feed belt.

Abstract: A conversion kit to adapt a single-feed continuous form paper press to dual-feed continuous form paper operation and thereby double production capacity. The kit includes infeed and outfeed bars which are attachable by their ends to corresponding pairs of drive pins of the infeed and outfeed tractors. Each of the bars is provided with a centrally located drive pin to project through overlapping perforated edge portions of both of the continuous form papers being printed. Infeed and outfeed support arms are provided which support infeed and outfeed guides. The guides are movable into and out of position over the centrally located drive pins of the infeed and outfeed bars to maintain the overlapping perforated edge portions of the papers entrained on the centrally located drive pins.

Abstract: A document feed tractor has a multiposition lid which is held by projections from the frame of the tractor in open position to enable loading of the perforated document (paper) in the tractor. The lid is pivotally mounted in openings in the projections which enable lid to be both rotated and translated from the open position over the projections, which then define ledges holding up the lid, to closed position when the lid is moved over the edges of the ledges. Then, the lid can snap down under a spring bias to the closed position where it confines the document on the tractor belt.

Abstract: A paper web-moving system includes a friction-type drive roll mechanism cooperatively operating with a detachable tractor drive mechanism. In one embodiment, the paper first passes over and engages a pair of driven tractors at an angle with respect to the horizontal, then under a driven roller platen and between two spaced apart sets of rollers positioned to force the paper against the roller platen. The drive mechanisms are configured so that the paper drive rate of the roller platen is greater than the drive rate of the tractor, causing paper tension therebetween. The present system permits the use of friction roll paper, tractor fan fold paper, and single sheets with a short tear-off capability.