Abstract: A coating is produced by a method including a screen printing of a photopolymerizable composition on a printed circuit board, illuminating said composition to partially polymerize it and bake it to complete the polymerization.The composition used by said method contains a reaction product of a monoethylenically unsaturated carboxylic acid with a material of the group of epoxy resin and epoxidized novolak, a phenoxy resin, a thickening agent, a polyethylenically unsaturated compound, a photo-initiator and a solvent.The coating produced according to this invention is used as solder mask.

Abstract: A high density electronic circuit module which includes a thin flexible film chip carrier having circuitry on both sides thereof. The double-sided thin, flexible circuitry is fabricated by depositing a first layer of chrome-copper-chrome circuitry on an aluminum substrate. This first layer of chrome-copper-chrome circuitry is covered with a layer of polyimide. Vias are etched into the polyimide. Next, a second layer of chrome-copper-chrome circuitry is deposited on top of the polyimide. The first and second layers of circuitry are connected through the etched vias. Finally, hydrochloric acid is utilized to etch away the aluminum substrate carrier. It is noted that hydrochloric acid etches aluminum whereas it does not etch chrome-copper-chrome circuitry.

Abstract: A high performance, low cost variable reluctance stepper motor has an integral structure with a ring and a plurality of aligned salient pole members. A plurality of teeth are located on the face of each pole member. Windings are disposed on alternate ones of the pole members and a high impedance means isolates the pole members from one another. A rotor with a plurality of teeth and a plurality of holes disposed thereon coacts with the pole members and is moved in a step fashion by the sequential energization of the windings. The flux generated by the energization of the windings is confined to a short path and coupling to the remainder of the structure is negligible. Recesses positioned symmetrically around the structure also serve to enhance flux splitting and reduce adjacent flux coupling.

Abstract: A strain relief device is provided for use with a printed circuit card which has a plurality of circuit elements thereon which are soldered to the ends of wire conductors carried in a cable. The device comprises a pair of identical elongated clamp members each having locking elements which enable the members to be aligned on opposite sides of the card and snapped into locking engagement with the conductors clamped therebetween.

Abstract: An improved centrifuge assembly comprising a channeled rotor assembly and a fluid container disposed in the channel, whereby the centrifugal separation effects in the fluid container are determined by the geometry of the channel in the rotor. This arrangement is particularly useful for two-stage blood platelet separation. The fluid container is preferably formed from semirigid plastic material and is considered a disposable item to be discarded after a single use. The rotary assembly preferably includes a removable filler piece or center piece formed from a single piece of material, such as rigid plastic, as by machining or molding, and having therein an open-topped channel having dimensions appropriate to receive the semirigid container, which is suitably curved and placed in the channel. Fluid connections are provided from each end of the container and an intermediate point to an axially located multichannel rotating seal. The connections lie in a plurality of radial slots in the filler piece.

Abstract: A data processing system including at least one channel and a multilevel store has the capability of performing a channel write to main memory where the data to be written into main memory crosses a double word boundary in a partial write store. The partial write store is accomplished by a merge operation which takes place in the memory system in a manner such that the main processor, channel and a cache store are freed up for further operation prior to the completion of the write to main memory.

Abstract: A serial disk printer which includes an ink roll is disclosed. During printing, the print disk is continuously rotated at a constant speed as it moves across the print line. The motion of the carrier across the print line does not begin until rotation of the print disk has been brought up to speed. In order to avoid unnecessary delay, the rotation of the print disk is not immediately stopped at the end of each line of printing. Instead, after each line of printing the carrier is returned to a home position and the disk is rotated for several seconds so that in the event printing of another line is required shortly after the completion of a line of printing the disk is still rotating and there will not be any delay before printing can begin. Ink is applied to the print disk by an ink roll which is in contact with the print disk. A mechanism is provided to lift the ink roll from the print disk while the disk is idling in home position. Thus, there is no wear on the ink roll while it is in home position.

Abstract: A serial printer which includes a print element which traverses back and forth in front of the paper. The print element is in the shape of a cup. The sides of the cup are formed by a plurality of fingers, each of which has a number of characters thereon. A hammer is located in the center of the cup. The fingers can be selectively raised whereby any one of the characters on each finger can be moved to the print position. Printing is accomplished by rotating the cup so that the desired finger is located between the hammer and the paper. If necessary, the finger is raised so that the desired character is positioned in the print position. The hammer is then fired to print the desired character.

Abstract: A rotatable print disk is mounted on a carrier which traverses along the print line. The disk is moved from each character position to the next by the shortest distance and it is stopped at the time of printing. The carrier is moved from one print position to the next at a speed which is selected depending on the time required for the disk to rotate to the next character. Printing takes place with the carrier moving at one of a number of speeds. Hammer firing is timed dependent on printing speed.