GB377314A - Improvements in or relating to air compressors of the multi-cylinder reciprocating type - Google Patents

Abstract

377,314. Air compressors. RICARDO, H. R., 21, Suffolk Street, Pall Mall, London. April 28, 1931, No. 12513. [Class 8 (i).] A multiple-cylinder compressor is provided with sleeve valves controlling the inlet and outlet ports and with unloading means whereby the cylinders are put into communication. The compressor pistons F work on cranks at 180‹ so that the sum of the volumes of the compression spaces is substantially constant. The cylinders have sleeve valves E with admission ports E<2> and delivery ports E<3> which during the oscillating and reciprocating motion of the sleeves communicate respectively with inlet ports C communicating with a supply passage C<1> and outlet ports D<1> arranged between the cylinder heads D and the cylinder liners B<1> and communicating with outlet chambers H which communicate through a passage H<1> with the delivery pipe H<3> through a spring-pressed valve H<4> provided with a dashpot. The sleeve valves are driven through toothed gearing from half-speed shafts. The cylinder heads are provided with unloading valve D3 which when open put the cylinders into communication and the delivery ceases. The valve H<4>, which normally remains open, closes and stops the backflow of air. The valves D3 are raised by levers K operated by a piston L mounted in a cylinder L<1> arranged in an oil chamber M, Fig. 3. The piston is pressed up by a spring L<3>, and the cylinder is open to the oil. The chamber M is put under atmospheric pressure or delivery pressure by a piston valve N<2> loaded by a weight N<6> and subject to the delivery pressure through a pipe N<1>.