Abstract: A second frame 12 is arranged at a predetermined position with respect to a drive sprocket 15 engaged with a drive shaft DS through a substantially true-circular hole shape drive bearing bore 14, and a transferring belt 25 is supported by a belt guide 18 integrally incorporated with the second frame 12 under a suitable tension while a predetermined positional relationship is maintained between the transferring belt 25 and the drive sprocket 15.

Abstract: A paper feeding tractor in which perforated paper is fed by a pin carrying feed belt includes a feed belt driving sprocket which is housed between a pair of side frames. 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 protuberances concentric with an axial hole therein such that the inner circumferential portion of the sprocket body is thinner than the outer circumferential portion. Thus, contact between the sprocket and the drive shaft is reduced to a relatively small sliding resistance. Paper can be moved in the axial direction of the drive shaft by a small force. During paper feed, any phase difference in rotation between the drive shaft and the sprocket can be eliminated. Alternatively, the feeding sprocket and a belt reception rotary member are housed within an auxiliary frame structure which is fit within and longitudinally slidable with respect to the main frame structure.

Abstract: A paper feed apparatus including a pair of side frames connected together so as to face one another with a predetermined gap therebetween, an endless feed belt mounted between the pair of side frames, a driving sprocket engaged with the endless feed belt and mounted between the pair of side frames at a first end thereof, and a belt receiver mounted between the pair of side frames at a second end thereof and supporting the endless feed belt. The driving sprocket and belt receiver have the endless feed belt trained thereabout with a predetermined amount of slack, such that the upper and lower runs of the belt are substantially linear. A feed belt supporter is mounted to the pair of side frames so as to contact an outer surface of and support the lower run of the endless feed belt so as to prevent the predetermined slack from gathering at the lower run of the endless feed belt.

Abstract: A clamp for a paper feed tractor for clamping a paper feed tractor to a support shaft. Such a clamp is used for clamping the paper feed tractor to the support shaft at a predetermined distance from another paper feed tractor which corresponds to a width of a perforated paper to be fed by the tractors. The clamp comprises a cylindrical holder member which is cantilevered from a frame of the paper feed tractor, and a cylindrical clamp member rotatably mounted about the holder member. The holder member comprises a pair of semi-cylindrical holder plates, each of which has two outer peripheral surface portions of differing radii and a sloped outer peripheral portion joining the two outer peripheral surface portions. The larger radius outer peripheral surface portion of each holder plate is arranged diametrically opposite from the other.

Abstract: In a sheet feed tractor, a lid confines a paper sheet on a frame surface when the paper sheet is conveyed on a belt. The lid is constructed so that it can overrun and return to its normal open position. The lid is constructed so as to include a lid member rotatable between a closed position spaced closely adjacent the surface of the frame so as to confine the paper sheet and an open position spaced away from the surface. The lid member has at one side edge thereof a pair of hinge pins disposed with a space therebetween and projecting over one side of the frame. The frame includes a pair of hinges projecting from one side of the frame and has the hinge pins of the lid member rotatably mounted thereto. The hinges of the frame include grooves opening towards the outside of the sheet feed tractor and are adapted to pivotally receive the hinge pins of the lid member.

Abstract: A cover is disclosed for a paper feed tractor having first and second side frames, a paper receiving plate extending perpendicularly from the second side frame and having a hole formed therein, and a paper exhaustion detector mounted to the second side frame. The paper exhaust detector of the paper feed tractor includes a microswitch with an upwardly biased plunger, and an actuator pressed upwardly by the plunger and pivotable between a first position in which it detects the presence of paper and a second position in which it detects the absence of paper. The cover of the present invention includes a plate, and elongated ribs projecting downwardly from the bottom surface of the plate on opposing sides of an elongated slot formed through the plate.

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 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: A paper feed tractor comprising a main frame, a sub frame secured to the main frame with a major portion thereof and disposed in parallel to the main frame, and a belt driving unit supported for sliding movement between the main and sub frames. The main and sub frames have first openings formed in a coaxial relationship at locations adjacent one end portions thereof so as to loosely fit a drive shaft therein and second openings formed in a coaxial relationship at locations adjacent the other end portions thereof so as to support a support shaft for sliding movement and for fixation therein. The belt driving unit includes a belt driving sprocket wheel supported for rotation on a plate-formed belt receiving member, and an endless belt extends between the sprocket wheel and a belt guide formed on the belt receiving member.

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 feed tractor comprising a tractor frame including a pair of side frames and a belt guide disposed between and coupled to the side frames, a sprocket wheel supported for rotation between the two side frames, an endless belt adapted to be driven by the sprocket wheel to slidably travel on guide walls formed on three peripheral faces of the belt guide, and a cover mounted at a side thereof for pivotal motion on one of the side frames from and to a position in which it extends on a linear one of the guide walls of the belt guide. The endless belt has feed pins provided projectingly in a row at equal intervals on an outer peripheral face thereof, and a paper holder provided on the cover is positioned, on at least one side of the feed pins, in parallel to the outer peripheral face of the endless belt.

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: 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: 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 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 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 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.