The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 14, 1986
Filed:
Jun. 09, 1983
Ronald Siegrist, Oberuzwil, CH;
Vickers, Incorporated, Troy, MI (US);
Abstract
A hydrostatic or pneumatic drive for driving a mass to be accelerated and decelerated, such as in a die casting or injection moulding machine, has a controllable valve arrangement which is operable to vary the fluid flow rate therethrough. The fluid flow rate is controlled by a reference value control generator operable to produce a ramp having superimposed thereon further control pulses. Such control pulses are a positive control pulse at the beginning of the rising slope and at the end of the falling slope of the ramp and a negative control pulse at the end of the rising slope and at the beginning of the falling slope of the ramp. Each control pulse has a volume which corresponds to a so-called compression volume factor which reflects the compressibility of the fluid used in the drive and also of the elasticity of ducts which expand by fluid pressure.