Abstract: Disclosed is drive apparatus especially useful for controllably displacing the carrier of a printer, the drive apparatus including a lead screw having laterally spaced apart and floating threaded followers thereon. Intermediate the threaded followers are a first pair of preloaded springs which press the followers against the opposite flanks of the threads on the lead screw to thereby inhibit backlash intermediate the followers. A second pair of springs are mounted intermediate a bracket, which is fastened to the carrier, and at least one of the followers for effecting coupling between the carrier and the follower while controlling backlash therebetween. A pair of arms extend from the followers and are coupled to a restraining shaft in such a manner as to inhibit rotational movement of the arms (and thus the followers) while permitting motion of the followers in any perpendicular direction to the lead screw to accommodate runout or eccentricity.

Abstract: A field replaceable encoder including a slotted housing having a pair of passages therethrough essentially perpendicular to the longitudinal axis of the housing, is attachable to the frame of a machine having a rotatable shaft to which the encoder is to be mounted. Attached to the housing is an accurate stationary mask, the mask having slits which are aligned with the passages in the housing. The mask includes an accurately dimensioned aperture for locating the mask, and thus the housing, on a bearing on the rotatably mounted shaft. A pair of light sources and a pair of light detectors are mounted on opposite sides of the housing aligned with the passages and slits in the mask. A hub, to which is attached a rotating disc, is connected to the rotating shaft, the disc being mounted in the slotted housing so that interdigitated opaque and transparent portions align with the slits of the mask, and thus the light sources and light detectors.

Abstract: Disclosed is the design for an aspirator (10) of a continuous stream ink jet printer. With reference to FIG. 1, the aspirator includes a tunnel configuration (20) wherein the tunnel cross-sectional area diverges from the inlet (23) to the outlet (22), the axial area gradient being inversely proportional to the intended velocity of air through the tunnel (20) so that the cross-sectional area of the outlet (22) is greater than the cross-sectional area of the inlet (23). In this manner, air movement through the tunnel (20) is substantially constant.

Abstract: A sheet paper feed apparatus for a typewriter having a frame supporting a platen for holding and providing at least longitudinal motion to a sheet of paper. A rectangular tray includes forward and rear paper supports for supporting a stack of paper thereon. Therebetween is a shinglar roll or wheel which supports the central portion of the paper stack is a slightly bowed configuration. The shinglar wheel is first driven in a rearward fashion to effect removal of the forward or leading edge of the bottom most sheet from the stack away from the forward support, and then the shinglar wheel rotation is reversed effecting feeding of the sheet of paper away from the bottom of the stack and below the forward paper support into paper feed rolls and ultimately onto the platen.

Abstract: Disclosed is a spring operating beyond the elastic limit of the material of which it is constructed, the spring including a length of resilient material having terminal end portions and a central body portion, one of the terminal end portions being adapted for connection to a first member. A convoluted portion of the resilient material has a central axis substantially perpendicular to the body portion and is adapted for connection to a second member, at least the convoluted portion being dimensioned so that upon separation of the first and second members due to a predetermined load, the convoluted portion uncoils and is stressed beyond the yield point of the material so that a substantially constant load placed on the convoluted portion by member separation effects further uncoiling of the convoluted portion.

Abstract: Disclosed is a cartridge and a cartridge assembly for a typewriter, the assembly comprising a pair of case members, each case having a separate chamber and including means for releasably connecting the two cases in superimposed overlapping relation. First and second pairs of spaced apart ribbon guide means are associated with each of the cases and dimensioned to be aligned, first pair to second pair. Each of the case members includes a separate supply and take-up spool, the supply spool having a fixed axis of rotation and the take-up spool having a shiftable axis of rotation along a translatory path. An opening is provided along one edge of each of the cases, the openings being aligned in the paths while the take-up spools are biased in their respective paths towards the opening.

Abstract: In a daisy wheel or rotary print wheel typewriter, a single motor (stepper motor) is employed to accomplish both ribbon lift and feed for typewriter ribbon and correction ribbon loaded in a cartridge assembly. A single motor drive moves a cartridge assembly support about an axis to present either the typewriter ribbon or the correction ribbon to the print point at the print line. In the first portion of the arc that the cartridge assembly moves, normal typing on the typewriter ribbon occurs, only the feed ratchet for the typewriter ribbon being engaged. Alternately, when the rotation is greater, to present a correction ribbon at the print line, the added elevation of the cartridge assembly causes disengagement of the normal ratchet feed for the typewriter ribbon but allows advancement of the correction ribbon.

Abstract: A boat or ship anchor having a crown portion with a spaced apart pair of flukes projecting forwardly therefrom in the same plane, and a pair of tail plates extending rearwardly therefrom, the tail plates being splayed to present a large frontal area. Intermediate the flukes and extending through the crown is an aperture. A shank element, adapted for attachment to the anchor line at its forward end, extends through the aperture and is dimensioned for sliding relation in the aperture intermediate the flukes. A projection in the form of a minor fluke on the tail end of the shank element limits the sliding motion of the shank through the aperture in a first direction while permitting limited rotational or angular movement thereof relative to the flukes and crown at least in a plane perpendicular to the plane of the flukes.

Abstract: In a typewriter, a ribbon is contained within a cartridge which is in turn placed upon the ribbon mechanism support of the typewriter. The cartridge is maintained rigidly clamped to the support but readily releasable by means of operator actuation of a release lever. The cartridge may either be a single cartridge or may be stacked such as where two cartridges are utilized together, one containing a print ribbon, the other containing, for example, a correction ribbon. The cartridge containing the print ribbon is provided with a bottom plate or surface which is formed to define an aperture therein for the admission of a clamping member attached to the support. The clamping member is inserted into the aperture and then caused to rotate about its axis a part turn at which point the clamping member engages an inclined surface on the interior of the cartridge causing the cartridge to be wedged downward against the support.

Abstract: Disclosed is an ink system for an ink jet printing apparatus having a replaceable ink bottle ink supply and a receptacle for receiving the ink bottle for coupling of the bottle to the ink system of the printer by an ink supply line. The improved apparatus includes an air purging pump for inhibiting air entry into the ink supply line occurring during ink bottle changes. A syringe type needle is provided in the base of the receptacle for providing fluid communication with the interior of the ink bottle, the air purging pump being placed intermediate the needle and the ink supply line.

Abstract: Each ink droplet printed on a recording surface, which has relative movement along a first axis with respect to ink droplet producing means, forms part of a character, and may be disposed in any granular position in a second direction, which is substantially orthogonal to the first axis, relative to a single predetermined position, which is the gutter stream position. Information concerning the location on the recording surface of each printed droplet relative to the single predetermined position in the second direction and to the prior printed droplet or a margin along the first axis is stored in a read-only storage (ROS). The information concerning the location of the droplet in the second direction is a voltage applied to charging means with the magnitude of the voltage in conjunction with any induction created by prior adjacent droplets of the ink stream determining the deflection of the droplet.

Abstract: Disclosed is a cartridge and a cartridge assembly for a typewriter, the assembly comprising a pair of case members, each case member having a separate chamber and including means for releasably connecting the two case members in superimposed overlapping relation. First and second pairs of spaced apart ribbon guide means are associated with each of the case members and dimensioned to be aligned, first pair to second pair. Each of the case members includes a separate supply and take-up spool, the supply spool having a fixed axis of rotation and the take-up spool having a shiftable axis of rotation along a translatory path. An opening is provided along one edge of each of the case members, the openings being aligned in the paths while the take-up spools are biased in their respective paths towards the opening.

Abstract: A variable pitch marine propeller having a plurality of circumferentially spaced apart blades mounted on axles at the root portion of the blades in a hub to permit independent movement of each of the blades about an axis of rotation substantially parallel to the axis of the hub between a first nested position adjacent the hub and a second extended position. Each of the blades includes leading and trailing striking surfaces or root segments on the root portion of the blades which are hub engageable upon initial rotation of the blade in either direction. Intermediate the leading and trailing segments of the blades are positioned cushioning means which may be mounted in either the hub or the blade root segments for inhibiting the shock of engagement of the blades and the hub upon initial start up of rotation of the hub or upon a sudden reversal of rotation of the hub.

Abstract: An interactive ink jet printer prints characters of a language from left to right or right to left in accordance with the direction in which the language is normally written. The signals for the direction in which a motor, which moves ink droplet supply device relative to a recording medium, the signals from a grating, which indicates the direction of motion of the ink droplet supply device and its position relative to a reference position, and the signals for the location of the ink droplet supply device at the reference position are changed whenever the direction of character printing is to be reversed.

Abstract: An improved sheet paper feed apparatus for a printing apparatus having a platen for holding and providing at least longitudinal motion to a sheet of paper. The sheet feed apparatus comprises a rectangular tray including a rear paper support portion and a spaced apart forward paper support portion, the portions for supporting thereon the opposite ends of a stack of paper. A shingler wheel is positioned intermediate the support portions for engaging the lowermost sheet of the paper sheet stack, and the shingler wheel is rotated in a first direction to move the lowermost sheet of the stack away from the forward support portion until the lowermost sheet is no longer supported thereby, and then in the opposite direction to drive the lowermost sheet beneath the forward paper support portion, the forward paper support portion comprising in the preferred embodiment a pair of inwardly projecting, spaced apart fingers.

Abstract: In a ribbon cartridge for retaining and supporting a ribbon in a typewriter, the cartridge comprising spaced apart top and bottom walls and a sidewall joining the top and bottom walls adjacent the periphery thereof to form a chamber. The sidewall of the cartridge is discontinuous at predetermined locations to form at least entrance and exit apertures for the ribbon, and at least a ribbon take up spool is provided in the chamber in communication with the ribbon entrance aperture to take up used ribbon passing through the entrance aperture.

Abstract: In a typewriter environment, a carrier mounted sensor for calculating the width of a sheet of paper on the platen and for thereafter setting-up margins for that sheet of paper. In addition to supporting the sensor, the carrier supports the printhead and associated apparatus for detecting the position of the carrier relative to the platen at each escapement position of the carrier. The sensor starts its scan at the extreme left position of the carrier and senses the left edge of the paper at a transition from dark-(the platen surface) to-light (the sheet of paper). This transition point is detected and stored. The carrier continues its rightward scan and the right edge of the sheet of paper signals a transition from light-to-dark. This position is detected and stored. The carrier and sensor continue scanning to the right for a specific distance to eliminate errors that are caused by dark areas on the paper that prematurely trigger light-to-dark transitions.

Abstract: Disclosed is a digital escapement control system in which the motor (DC) control is completely digital requiring no tachometer generation of feed back signal nor any analog to digital convertors. Connected to the DC motor shaft is a code wheel and detector to determine the time between discreet positions of the motor shaft as it rotates. The time between discreet positions is then compared with a desired time, and the difference is stored, as by a register. The difference is then converted to a pulse-width-modulated (PWM) signal which directly controls the rotational velocity of the motor, increasing or decreasing it as necessary. The system operates, in a ramp, open loop start up mode and digital velocity controlled braking mode while in the motional mode with the feed back as described above. At start up, provision is made for inserting the feed back loop when the velocity reaches some predetermined level or percentage of the desired velocity.

Abstract: In a typewriter environment, a carrier mounted sensor for calculating the width of a sheet of paper on the platen and for thereafter setting-up proportional margins for that sheet of paper. In addition to supporting the sensor, the carrier supports the printhead and associated apparatus for detecting the position of the carrier relative to the platen at each escapement position of the carrier. The sensor starts its scan at the extreme left position of the carrier and senses the left edge of the paper at a transition from dark (the platen surface)-to-light (the sheet of paper). This transition point is detected and stored. The carrier continues its rightward scan and the right edge of the sheet of paper signals a transition from light-to-dark. This position is detected and stored. The carrier and sensor continue scanning to the right for a specific distance to eliminate errors that are caused by dark areas on the paper that prematurely trigger light-to-dark transitions.

Abstract: Disclosed is an ink jet printer head employing an ink droplet aspirator which includes a housing having a tunnel therein spaced from an ink jet nozzle which emits a stream of ink droplets which pass through the tunnel. A gas stream is also directed through the tunnel at substantially the same velocity as the ink stream. While the upper and lower walls of the aspirator tunnel are formed of sintered metal thereby forming the deflection electrodes, the sidewalls of the tunnel are formed of a dielectric material and are made movable, for example by collapsing toward and away from the tunnel top and bottom walls (deflection electrodes) so as to inhibit sidewall contamination during start up and shut down of the ink stream.