  Context. Open clusters are ideal test particles to study the chemical
evolution of the Galactic disc. However the existing high-resolution abundance
determinations, not only of [Fe/H], but also of other key elements, is largely
insufficient at the moment. Aims. To increase the number of Galactic open
clusters with high quality abundance determinations, and to gather all the
literature determinations published so far. Methods. Using high-resolution
(R~30000), high-quality (S/N$>60 per pixel), we obtained spectra for twelve
stars in four open clusters with the fiber spectrograph FOCES, at the 2.2 Calar
Alto Telescope in Spain. We use the classical equivalent widths analysis to
obtain accurate abundances of sixteen elements: Al, Ba, Ca, Co, Cr, Fe, La, Mg,
Na, Nd, Ni, Sc, Si, Ti, V, Y. Oxygen abundances have been derived through
spectral synthesis of the 6300 A forbidden line. Results. We provide the first
determination of abundance ratios other than Fe for NGC 752 giants, and ratios
in agreement with the literature for the Hyades, Praesepe and Be 32. We use a
compilation of literature data to study Galactic trends of [Fe/H] and
[alpha/Fe] with Galactocentric radius, age, and height above the Galactic
plane. We find no significant trends, but some indication for a flattening of
[Fe/H] at large Rgc, and for younger ages in the inner disc. We also found a
possible decrease of [Fe/H] with |z| in the outer disc, and a weak increase of
[alpha/Fe] with Rgc.
