Variable orifice outlet assembly

Abstract

A pumping system comprises a pump, first and second channels, a valve, and an actuator. The pump pumps fluid according to a pumping cycle. The first channel has a first fluid flow orifice with a first diameter, while the second channel has a second fluid flow orifice with a second diameter greater than the first diameter. The valve is configured to direct fluid from the pump to the first channel in a first state, and to the second channel in a second state. The actuator is configured to switch the valve into the first state during a high pressure period of the pumping cycle, and into the second state during a low pressure period of the pumping cycle.

1 . A pumping system comprising:
 an pump that pumps a fluid according to a pumping cycle;   a first passage with a first orifice having a first diameter;   a second passage with a second orifice having a second diameter greater than the first diameter;   a valve configured to direct the fluid from the pump to the first passage in a first state, and to the second passage in a second state; and   an actuator configured to switch the valve into the first state during a high pressure period of the pumping cycle, and into the second state during a low pressure period of the pumping cycle.   
     
     
         2 . The pumping system of  claim 1 , wherein the first orifice is disposed through a first removable plug in the first passage, and the second orifice is disposed through a second removable plug in the second passage. 
     
     
         3 . The pumping system of  claim 1 , wherein the actuator comprises an electronic switch. 
     
     
         4 . The pumping system of  claim 3 , wherein the electronic switch actuates the valve in response to sensed pressure readings from the pump. 
     
     
         5 . The pumping system of  claim 3 , further comprising:
 a pump motor configured to drive the pump; and   a controller configured to control the pump motor and the electronic switch according to the pumping cycle.   
     
     
         6 . The pumping system of  claim 1 , wherein the actuator comprises a hydraulic switch. 
     
     
         7 . The pumping system of  claim 6 , wherein the hydraulic switch is controlled by a hydraulic pilot line driven by changes in pressure in the pump. 
     
     
         8 . The pumping system of  claim 1 , wherein the pump is a double-action piston pump. 
     
     
         9 . An adhesive system comprising:
 a melt system for melting adhesive;   a pump disposed to pump the adhesive from the melt system according to a pumping cycle;   a dispenser configured to receive and dispense the adhesive from the pump; and   an outlet assembly disposed between the pump and the dispenser to smooth melted adhesive pressure at the dispenser by routing the adhesive through a first diameter orifice during a first portion of the pumping cycle, and through a second diameter orifice during a second portion of the pumping cycle.   
     
     
         10 . The adhesive system of  claim 9 , wherein the first diameter orifice has a narrower diameter than the second diameter orifice, and wherein the outlet assembly further comprises a valve disposed to route the adhesive through the second diameter orifice during changeover of the pump, and through the first diameter orifice otherwise. 
     
     
         11 . The adhesive system of  claim 10 , wherein the valve is a shuttle valve. 
     
     
         12 . The adhesive system of  claim 10 , wherein at least one of the first and second diameter orifices is situated in a removable plug. 
     
     
         13 . The adhesive system of  claim 9 , further comprising a supply hose configured to carry adhesive from the outlet assembly to the dispenser. 
     
     
         14 . An outlet assembly for a pump, the outlet assembly comprising:
 an inlet plenum disposed to receive fluid from the pump;   an outlet plenum disposed to supply fluid to a downstream component;   a first orifice fluidly disposed between the inlet and outlet plena, and having a first orifice diameter;   a second orifice fluidly disposed between the inlet and outlet plena, and having a second orifice diameter greater than the first orifice diameter;   a valve with two valve states:
 a first valve state routing fluid from the inlet plenum to the outlet plenum via the first orifice; and 
 a second valve state routing fluid from the inlet plenum to the outlet plenum via the second orifice; and 
   an actuator configured to switch the valve from the first valve state to the second valve state during changeover of the pump.   
     
     
         15 . The outlet assembly of  claim 14 , wherein the first orifice is situated in a first passage connecting the inlet and outlet plena, and the second orifice is situated in a second passage connecting the inlet and outlet plena. 
     
     
         16 . The outlet assembly of  claim 15 , wherein the valve is a shuttle valve disposed to open the inlet plenum to either the first passage or the second passage. 
     
     
         17 . The outlet assembly of  claim 14 , wherein the downstream component is a fluid dispenser. 
     
     
         18 . The outlet assembly of  claim 14 , wherein the fluid is hot melt adhesive. 
     
     
         19 . A method for controlling outlet pressure of a pump having a pumping cycle, the method comprising:
 directing fluid through a first orifice during a high pressure period of the pumping cycle corresponding to a sustained pump stroke; and   directing fluid through a second orifice wider than the first orifice during a low pressure period of the pumping cycle corresponding to pump changeover.   
     
     
         20 . The method of  claim 19 , wherein:
 directing fluid through the first orifice comprises switching a valve to a first valve state that fluidly connects the pump to the first orifice; and   directing fluid through the second orifice comprises switching the valve to a second valve state that fluidly connects the pump to the second orifice.   
     
     
         21 . The method of  claim 20 , further comprising actuating the valve based on pressure in the pump.