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:
Jul. 19, 1988
Filed:
Jan. 07, 1987
Alcon Laboratories, Inc., Fort Worth, TX (US);
Abstract
A system 10 for proportional control of a pneumatic cutting device 13 includes a linear solenoid valve 11 having a flow rate therethrough proportional to the current passing through the solenoid 32. The linear solenoid valve 11 is actuated by a selectively varied electrical signal generated by a power supply 18 and controlled by a potentiometer 14 which is itself operated by a pedal foot controller 16. Regulated fluid pressure is fed through the linear soleoid valve 11 to a pneumatic cutting device 13 such as an intraocular microscissors which closes increasingly as the applied pressure increases. The linear solenoid valve 11 includes a flow path which is variably constricted or closed by a valve member 36, and a solenoid 32 which is arranged to pull the valve member 36 to open the flow path. An elastic member 35 is disposed to resiliently bias the valve member to the closed position; the linear restoring force of the elastic member provides a generally linear relationship between the fluid flow-through rate and the current through the solenoid 32, and a proportional relationship between the control pedal position and closure of the cutting device.