Abstract: In a continuously variable transmission (“CVT”) using a toroidal-race continuously variable ratio device and a planetary gear mechanism, the rotation of the input shaft (12) is directly transmitted to the carrier C of the planetary gear mechanism (61), and rotation resulting from gearing and reversal by the variator (5) is transmitted to the sun gear (S1). When the low clutch L is engaged, the rotation of the ring gear (R3) is transmitted via the reversing gear mechanism (71) to the output shaft (13), and when the high clutch H is engaged, the rotation of the sun gear (S2) is transmitted to the output shaft (13).

Abstract: Disclosed are Bisphenol A (BPA), Bisphenol F, Bisphenol A diglycidyl ether (BADGE), and Bisphenol F diglycidyl ether (BFDGE)-free coating compositions for metal substrates including an under-coat composition containing a polyester (co)polymer, and an under-coat cross-linker; and an over-coat composition containing a poly(vinyl chloride) (co)polymer dispersed in a substantially nonaqueous carrier liquid, an over-coat cross-linker, and a functional (meth)acrylic (co)polymer. Also provided is a method of coating a metal substrate using the BPA, BPF, BADGE and BFDGE-free coating system to produce a hardened protective coating useful in fabricating metal storage containers. The coated substrate is particularly useful in fabricating multi-part foodstuffs storage containers with “easy-open” end closures.

Abstract: In a continuously variable transmission (“CVT”) using a toroidal-race continuously variable ratio device and a planetary gear mechanism, the rotation of the input shaft (12) is directly transmitted to the carrier C of the planetary gear mechanism (61), and rotation resulting from gearing and reversal by the variator (5) is transmitted to the sun gear (S1). When the low clutch L is engaged, the rotation of the ring gear (R3) is transmitted via the reversing gear mechanism (71) to the output shaft (13), and when the high clutch H is engaged, the rotation of the sun gear (S2) is transmitted to the output shaft (13).

Abstract: A continuously variable ratio transmission (CVT) comprises a ratio varying unit (“variator”), a first epicyclic (18) having two inputs (A2, S2) connected to opposite sides of the variator (V), a second. epicyclic (16) having an input (C1) driven by a prime mover (12) and components (A1, S1) connected to opposite sides of the variator, a final drive shaft (14), a low regime clutch (L) for selectively connecting the output of the first epicyclic to the final drive shaft in low regime and a third, mixing, epicyclic (20) connected to the output (C2) of the first epicyclic (18) and connected or connectable (F, R) to the variator and being connectible with the final drive shaft in high regime by way of a high regime clutch (F). The high and low regimes are coincident at least one variator ratio (or, more preferably, the operation ranges overlap) and the variator operates in opposite directions in the low and high regimes.

Abstract: An optical waveguide device for guiding an optical signal comprising a substrate, a waveguide extending at least partially across the substrate, and at least two slots extending transversely across the waveguide. The separation between the slots, the direction of propagation of the optical signal in the waveguide, is substantially ( n ⁢   ⁢ Δ ⁢   ⁢ λ 2 ) , where n is an odd integer and &Dgr;&lgr; the difference in wavelength of the radiation and guided modes of the optical signal resolved in the direction of propagation.

Abstract: An arrayed waveguide grating device 1 has a substrate 1 with an array 41 of waveguides extending across the substrate between an input coupler 37 and an output coupler 39. At least one input waveguide 31 extends between an input end for coupling to an input signal and the input coupler 37 and at least one output waveguide extends between an output end for coupling to an output signal and the output coupler 39. The input end or ends of the at least one input waveguide and the output end or ends of the at least one output waveguide are brought to the same edge 35 of the substrate.

Abstract: It is found that the use of a multimode interference (MMI) section to flatten the pass-bands of an arrayed waveguide grating (AWG) multiplexer/demultiplexer or comb filter device introduces undesirable wavelength dispersion into those pass-bands if that MMI section mixes modes of more than two different orders, and if the grating of that device is a ‘uniform’ grating whose waveguides are equally (minimally) attenuating, and in which the optical path length difference between each adjacent pair of waveguides 40 of the array is the same.

Abstract: It is found that the use of a multimode interference (MMI) section to flatten the pass-bands of an arrayed waveguide grating (AWG) multiplexer/demultiplexer or comb filter introduces undesirable non-linear wavelength dispersion into those pass-bands if that MMI section mixes modes of more than two different orders. This dispersion can be substantially compensated by the use of a tandem arrangement of two AWGs with MMIs of differing length chosen to provide complementary dispersions. In the case of a comb filter, an equivalent compensation can be achieved by arranging for the light to make a second passage through the AWG in the reverse direction.

Abstract: A channel insertion filter for a WDM system is provided by an optical waveguide Mach Zehnder comprising a pair of 3dB couplers interconnected by a pair of interference arms in which are created a pair of Bragg reflectors. These reflectors are partially reflecting at the channel insertion wavelength so that some of the light of the associated channel transmitter is transmitted by them to provide a feedback control loop error signal for regulating the emission wavelength of the transmitter.

Abstract: Optical fiber elements, such as narrow pass-band filters, dispersion equalizers, and channel dropping filters, are constructed from 2.times.2 single mode optical fiber fused tapered couplers having formed on one side of coupling regions Bragg distributed gratings in the two fibers from which the coupler is constructed. By making the gratings at a point where the fibers remain fused together in side-by-side contact it is ensured that they lie equidistant from the coupling region.

Abstract: An optical fibre amplifier in which a length of optically amplifying fibre is spliced between a pair of 2.times.2 tapered fused fibre couplers each constructed from a length of amplifier type profile fibre and a length of transmission type profile fibre. In each coupler, one of two constituent fibres has been pre-stretched so as to match the propagation constants of the two fibres within the coupling region of that coupler.

Abstract: A wavelength multiplexing tapered fused fibre coupler is used to splice a second length of optical amplifier fibre between first and third lengths in such a way that pump power bypasses it. The second length is therefore unpumped and acts as a notch filter smoothing out the spectral gain characteristic of the first and third lengths.

Abstract: In the manufacture of a wavelength multiplexing 2.times.2 tapered fused fiber coupler by progressive stretching, the birefringence of the coupler resulting from the progressive stretching is subsequently nulled-out by elastic twisting of the coupler. The progressive stretching is performed, under temperature conditions providing a profile in the coupling region of the coupler having the property that the coupling strength for one of the principal polarization planes of the coupler remains substantially constant during said elastic twisting.

Abstract: A 1.times.N single mode optical waveguide coupler comprises a single input optical fibre (1), a slab-like mixer waveguide (3) and a plurality (N) of output optical fibres (2). As a result of interference effects light introduced into the mixer waveguide (3) via the centrally located input fibre (1) produces a linear array of output spots at various intervals along the length of the mixer waveguide. The length of the mixer waveguide is chosen such that the output optical fibres are aligned with one such array of output spots. The fibres may be adiabatically tapered to a smaller diameter in order to increase their modal spot size.

Abstract: An active optical fibre star coupler having a length of amplifying optical fibre (1) optically connected at one end to a wavelength combining coupler (2) and at the other end to via a beam expanding element (3) to a set of output optical fibres.

Abstract: A method of making a single mode optical fibre directional coupler in which a pair of fibres (30,31) in side-by-side contact is subjected to a succession of drawing operations produced by traversing the fibres longitudinally through a flame (34) while stretching them between a pair of carriages (32,33) driven at slightly different speeds.