Abstract:
A magnetic transducing head assembly with a magnetic head being maintained in contact with a record member during relative motion between the head and record member. The head is resiliently mounted on a pad by a diaphragm. A source of pressure produces a cushion of air which separates the pad from the record member by a desired distance with the head protruding from the pad by at least the desired distance. The diaphragm urges the head into contact with the record member when the pad is separated from the record member by the desired distance. In another embodiment, high and low pressure areas are produced to separate the pad from the record member and to maintain the head in contact with the record member.
Abstract:
An output amplifier is fed from a load via a F.E.T. preamplifier included in switching means for disabling conduction of F.E.T. pre-amplifier during application of certain input signals to the load.
Abstract:
Document feeding apparatus has provision for supporting a stack of documents above and spaced away from a vacuum feeding drum. A suction shoe is interposed between the stack and the drum and has a depression in that face nearer to the stack. The leading edge of the lowermost document of the stack is attracted into the depression so that it is separated from the stack and a knife is moved into the gap between the attracted edge and the stack to maintain the separation. The suction shoe is then withdrawn to allow the separated edge to move into contact with the vacuum drum which then withdraws the lowermost document completely from the stack. A refinement allows the thickness of document in the depression of the vacuum shoe to be examined in order to detect the separation of more than one document or to detect failure of a document to be separated before the feeding cycle is proceeded with.
Abstract:
A data-processing system is disclosed in which the distinction between data items and program instructions is largely eliminated. Information is stored as statements, each of which normally consists of a name, a value, and an indicator which defines the logical relationship between the name and the value. Two statements are compared and if predetermined parts of the two statements are the same, a part of one statement, which defines a processing operation, is carried out.
Abstract:
A servo control apparatus for controlling a paper tractor drive motor is described in which the current supply to the motor is controlled digitally so that for short movements a braking current is applied for the second half of the movement and for larger movements the braking current is applied at a predetermined distance before the required stopping point.
Abstract:
A magnetic transducing head assembly which includes spaced first and second gapped cores mounted on a body member. A first magnetic screen is located between and extends transversely of, the first and second cores. A second magnetic screen is mounted on the body member to provide a flux path between the first screen member and the core of the first head at a point spaced from the first head. Both said screens have a transverse width which is less than that of the body member.
Abstract:
A method of forming circuit interconnections between adjacent circuits of a multilayer circuit structure is described in which corresponding sets of solder protrusions carried on conductive tracks of adjacent circuits are separated by a layer of uncured, heat-curable insulating material having a transient state, in which the material becomes deformable, between the uncured and the cured states. The layer is heated and the circuits are urged towards one another during the transient, deformable state of the material so that the protrusions pierce the layer, corresponding protrusions contacting one another and the heat subsequently causing the material to become cured. Finally, the contacting protrusions are fused together.
Abstract:
Apparatus is disclosed for simultaneously lapping spaced parallel faces on a workpiece by means of an elongate lapping tool which has a plurality of spaced lapping faces. The lapping faces may be formed as a helical surface on the lapping tool so that rotation of the lapping tool results in the faces on the workpiece being lapped by a number of separate portions of the helical surface and results in the workpiece being moved along the lapping tool so that each face is lapped successively by a number of different portions of the helix.
Abstract:
A circuit for producing controlled pulses includes switch means for sampling a full wave rectified a.c. signal, the switch means passing a portion of each half cycle to an averaging circuit means to compare the output of said averaging circuit with a ramp voltage, the comparison means producing an output pulse upon said ramp voltage exceeding the output of said averaging circuit and feed back means responsive to said output pulses for controlling the operation of said switch.
Abstract:
In a display system for indicating error conditions in groups of registers. The names of a group of registers are carried on an exchangeable slide from which they are projected on to a screen. An array of lamps is positioned behind the screen, one lamp being associated with each register name. A code area on each slide is sensed to identify the particular group of registers corresponding to the names on the slide and to control the connection of each one to its associated lamp thus to provide a visual indication of the state of each register in the group.