The dashpot of this invention includes a substantially cylindrical glass tube in which travels a piston having a diameter slightly less than that of the interior of the tube. A modified liquid or gum defines the medium in the cylinder in which the piston is adapted to travel. The flow ingenerated in the cylinder is predominantly a pressure flow with the shear flow being relatively insignificant. The device of the present invention operates in the lubrication region whereby relatively small timers are capable of providing delays up to several months or more.
This application is a continuation-in-part of application Ser. No. 816,132, filed Dec. 9, 1968 which, now Pat. No. 3,563,023 in turn, was a continuation-in-part of application Ser. No. 770,215, filed Oct. 24, 1968, now abandoned.
The dashpot of this invention includes the substantially cylindrical cylinder in which travels a piston having a diameter slightly less than that of the interior of the cylinder. A liquid or modified liquid defines the medium in the cylinder in which the piston is adapted to travel. The flow ingenerated in the cylinder is predominantly a pressue flow with the shear flow being relative insignificant. The flow is also at sufficiently high Reynolds numbers such that inertial effects are present. The device of the prsent invention operates in the lubrication regime whereby relatively small timers are capable of providing time delays of up to several seconds or more.
A fluid operated timing device in which the timing interval is determined by the rate at which the fluid flows through a precisely configured rate control frit upon being forced through the frit by an energy source in the form of a compressible elastomeric member.
