Patent ID: 11904504
Assignee: AFROS S.P.A.
Field: Other special machines (Mechanical engineering)
Classification: CPC B  G | IPC B

Claim 31:
32. Method for manufacturing a high-pressure mixing device of a first and at least a second chemically-reactive liquid component, where it is provided to:
configure a delivery duct as a tubular element made in a single piece, having an open upper end and communicating with a spacer chamber and a lower end open for delivering a reactive mixture, and wherein said tubular element can be processed separately with respect to a head-body of said mixing device and is inserted with a clearance and removably locked—to allow an easy removal—in a pass-through hole in said head-body,
obtain on said tubular element, before inserting it into said head-body, an intermediate transversal hole intended, in an assembled configuration, to extend a mixing chamber of said head-body with an increased diameter to compensate for, while being assembled, errors of mutual geometrical positioning due to processing tolerances and avoid the presence of steps and zones interfering with the movement of a valve member slidingly movable in said mixing chamber, such that said mixing chamber extends up until it leads into a delivery chamber internally delimited within said tubular element;
obtain in a cylindrical surface of said intermediate transversal hole in the thickness of said tubular element an annular seat with an outer saddle-shaped profile,
forcedly house and compress in said annular seat a sealing element of suitable shape to be inserted with interference towards all the surfaces of said seat, so as to exert the function of hydraulic sealing against leakages of reactive components from longitudinal recirculating slots of said valve member towards said delivery duct and against leakages of lubricant liquid from a gap—defined between the control stem of a cleaning member slidingly movable in said mixing chamber and said tubular element—towards said longitudinal recirculating slots when the front end part of said valve member is in an advanced position;
provide sealing and centering elements configured to maintain said tubular element in axially centered position and separated with respect to said pass-through hole of said head-body, avoiding metal-on-metal contact between respective cylindrical surfaces,
provide sealing gasket elements configured to avoid any leakage of polymeric mixture and of reactive components from said mixing chamber towards the interface between said head-body and said tubular element and towards said spacer chamber and to avoid any leakage of lubricant liquid from said spacer chamber towards said mixing chamber,
configure said tubular element with an annular shoulder zone placed at a zone distant from said intermediate transversal hole, and
removably fix, via fixing elements, said annular shoulder zone to a side surface of said head-body configured for locking in the correct position said tubular element in said pass-through hole,
apply strain gauge sensors of the resistance electrical type on an annular groove obtained on the outer cylindrical surface of said tubular element, or apply one or more strain gauge sensors on said annular groove and one or more strain gauge sensors on a recess seat obtained on a surface of said tubular element, orthogonal to the longitudinal axis of said tubular element.