Abstract: Sheets 12 are fed one at a time from a stack 11 by a freely mounted roller 13 magnetically coupled to a rotating drive roller 14. As the stack is depleted, an elevator 27 is operated to maintain the top sheet in contact with the roller 13.

Abstract: The tension imparted to an advancing strand 11 is regulated by passing the strand about a permanent magnet sheave 13 interposed between a pair of permanent magnet discs 19 and 21. The sheave and discs are axially polarized so that the magnet fields about the sheave are in opposing or repelling relation with the magnetic fields about the discs. By moving (26, 27 and 28) a disc toward or away from the sheave the intensities of the coupled lines of magnetic force are increased or decreased to accordingly vary the magnetic drag placed on the sheave and thus the tension imparted to the advancing strand 11.

Abstract: Two stacks of toroidal magnets (33, 34, 35 and 37, 38, 39) are coaxially mounted and polarized so that the first stack (33, 34, 35) is centered and spacially supported within the second stack (37, 38, 39). The second stack is mounted in a stationary base (26) while the first stack is mounted in a support (17) on which may be mounted clamps (16) for holding a workpiece, such as a printed circuit board. The board may be freely moved in a horizontal plane to position portions thereof relative to a work tool (18, 21). Any detrimental work forces imparted by operation of the work tool are dissipated by a tilting of the work support against the magnetic fields set up by the coaxial stacks of magnets.

Abstract: Two spaced stacks of magnetically soft E-cores, (17 and 18) are supported in spaced relation by pairs of magnets (38 and 39) on opposite sides of each stack. A pair of shuttles (41 and 47) move alternately toward and away from each other and under the stacks to pick off the lower core in each stack. The shuttles alternately advance the cores into a transformer frame (10) where a pair of magnets (66 and 67) are effective to hold the cores in an assembled position within the frame while the shuttles return for another E-core feeding operation. Entry of the cores into the frame is facilitated by a pair of rotating drums (71 and 72) having staggered arrays of magnets (78 and 79) which act to rapidly vibrate the E-cores (17 and 18) and thus prevent lodging of the cores against the frame.

Abstract: A test device includes a pair of test probes (21 and 22) which are manipulated onto a succession of test sites (11, 13 and 16) formed on a complex circuit board, and the operator is visually apprised of test results without loss of eye contact with the test sites. Visual appraisal is provided by a small light emitting diode (46) which is activated in accordance with the probed test results. The diode is mounted on the operator's safety glasses (58) and is of such size as to be not discernible when positioned inside the normal focal point of the operator's eye, but a glow is discernible when the diode is operated upon a particular test condition being ascertained by the test probes.

Abstract: A mechanical aerator comprising a boss, and at least one blade which extends radially from the boss and comprises a planar body portion and a deflector, the arrangement being such that when the aerator is mounted for rotation about a vertical axis the planar body portion of the blade lies in a vertical, or substantially vertical, plane and the deflector is inclined circumferentially upwardly from the top of the planar body portion.

Abstract: Several methods and apparatus are disclosed for successively loading a predetermined number of elongated paramagnetic articles out of a temporarily stored mass thereof, initially confined within a magnetic field-defined storage area in parallel relationship, into precisely spaced arrays, with each array thereafter being transferred to an unloading station whereat the articles are simultaneously released to fall by gravity into respectively aligned receiving areas of an associated workpiece positioned therebelow. As a common, reciprocally mounted, article handling mechanism is employed to carry out the loading, transferring and unloading operations, and as no inversion of the articles is required to effect the unloading thereof, the composite apparatus advantageously is of simplified, reliable and rugged construction.