Abstract: Seamless hand-off of air-to-ground telephony calls is achieved autonomously within an aircraft by using one of at least two radio links to search for additional ground stations. The search for candidate ground stations for hand-off is expedited by eliminating ground stations exhibiting zero or negative Doppler effects. Other values indicating quality of the link corresponding to the channel over which the search is conducted is compared with the quality of the call and an alternate call is established using the call identification code previously established for the call in progress. The hand-off of the call may then be easily conducted by transferring the voice signal to the channel over which the search was conducted. This is preferably done at a time when the transmission quality of the two channels would be approximately the same or the quality improved on the channel to which hand-off is made.

Abstract: A particularly configured aperiodic grid for a grid-controlled AC corona charger for uniformly charging a dielectric member, of an electrostatographic reproduction apparatus, moving along a travel path in operative relation to the corona charger. The corona charger includes an insulating housing and an electrically biased grid, in which the grid transparency is larger than a nominal transparency at the upstream edge of the charger grid, transparency is nominal at the center of the grid, and transparency is smaller than nominal at the downstream edge of a charger grid. The invention, which has been demonstrated for negative primary charging, preferably uses a trapezoidal AC waveform having a DC offset for corona excitation, and may be practiced over a large range of process speeds. The invention is also practiced using trapezoidal waveforms having negative duty cycles in the range 50% (conventional AC) to 90% (negative DC).

Abstract: A tandem axle vehicle suspension comprising a beam extending between and pivotally connected at each end to a respective one of a pair of axles and a spring acting between the beam and a vehicle mounting. The spring comprises a pair of springs the axes of which are inclined at equal and opposite angles to the vertical. Each spring comprises layers of elastomeric material interleaved with and bonded to reinforcing elements wherein at least some of the elastomeric layers and elements are curved about a common center of curvature.

Abstract: Resilient support means for securing a rail to a rail bed comprises a base member, a rail location member and resilient mounting means acting between the base member and rail location member.The rail location member has side portions which are inclined relative to the rail abutment surface so that lateral steering forces experienced by a rail result in a combination of shear and compression forces in the resilient mounting means.The side portions may be inclined at any angle in the range from 15.degree. to 45.degree. preferably 30.degree..The side portions may be inclined upwards and outwards relative to a center portion or they may be inclined downwards and outwards relative to the center portion.The rail location member has means for directly securing a rail to the rail abutment surface.The mounting means may comprise a single element or a plurality of elements made from a suitable elastomeric material.