Foam encased pump

Abstract

A compact pump has a uni-body, or alternately a two-part, housing of self-skinning foam construction for superior noise and vibration reduction, such as needed for medical nebulizer applications. The uni-body foam housing is formed by molding the housing around a pump assembly having special features designed to shield and space apart moving or sensitive internal components of the pump assembly from the foam during the insert molding process. The alternate two-part foam housing is assembled using a union ring having multiple barbed pins that fit into openings in mating faces of the two housing sections.

1 . A pump having a cylinder and piston disposed along a piston axis, the piston being driven to reciprocate within the cylinder along the piston axis and pass air through a valve head having an intake port and an exhaust port in communication with the cylinder and respective inlet and outlet ports of a housing being of molded foam construction and forming an internal cavity containing the cylinder and piston.  
   
   
       2 . The pump of  claim 1 , wherein the foam is self-skinning.  
   
   
       3 . The pump of  claim 1 , wherein the housing is of uni-body construction.  
   
   
       4 . The pump of  claim 3 , wherein the housing defines a handle.  
   
   
       5 . The pump of  claim 1 , wherein the housing includes first and second housing sections.  
   
   
       6 . The pump of  claim 1 , wherein the first and second housing sections have peripheral faces and are coupled together by a double sided union ring mated to the peripheral faces.  
   
   
       7 . The pump of  claim 6 , wherein the union ring is plastic.  
   
   
       8 . The pump of  claim 6 , wherein union ring is mated to the peripheral faces by pin and slot connections.  
   
   
       9 . The pump of  claim 8 , wherein the union ring has a first set of pins extending from one side and a second set of pins extending in an opposite direction from the first set from an opposite side such that the first set of pins is disposed in an associated plurality of openings in the peripheral face of the first housing section and the second set of pins is disposed in an associated plurality of openings in the peripheral face of the second housing section.  
   
   
       10 . The pump of  claim 9 , wherein the first and second set of pins have tapered locking barbs.  
   
   
       11 . The pump of  claim 6 , wherein the union ring in part defines the inlet of the housing.  
   
   
       12 . The pump of  claim 6 , wherein the peripheral faces of the first and second housing sections define a handle opening and wherein the union ring defines a handle opening aligned with the handle openings of the first and second housing sections.  
   
   
       13 . The pump of  claim 1 , wherein the housing includes a plurality of vent passages venting the internal cavity to ambient.  
   
   
       14 . The pump of  claim 1 , wherein the piston is driven by an armature of an electromagnet mounted within the housing by one or more springs.  
   
   
       15 . The pump of  claim 14 , wherein the electromagnet is contained within an electromagnet housing inside of the internal cavity of the housing.  
   
   
       16 . The pump of  claim 15 , wherein the electromagnet housing includes an opening in communication with a vent in the housing.  
   
   
       17 . The pump of  claim 15 , wherein the electromagnet housing has an open end that is closed by an end cap which defines an air volume in which a reciprocating component can move along the piston axis.  
   
   
       18 . The pump of  claim 17 , wherein the end cap is dome-shaped and has an opening in communication with a vent in the housing.  
   
   
       19 . The pump of  claim 1 , wherein the valve head includes a valve plate with an annular wall defining an air volume in which the cylinder is disposed.  
   
   
       20 . The pump of  claim 1 , wherein the annular wall has an opening in communication with a vent in the housing.  
   
   
       21 . A method of making a pump having a pump assembly including a cylinder and piston arrangement and a valve head having an intake port and an exhaust port in communication with the cylinder, the method comprising the steps of: 
 pre-assembling the pump assembly;    inserting the pump assembly into a mold die; and    molding a foam housing around the pump assembly.    
   
   
       22 . The method of  claim 21 , further including the step of allowing the foam cure and form a skin.  
   
   
       23 . The method of  claim 21 , further including the step of forming inlet and outlet passages in the housing in communication with the respective intake and exhaust ports of the valve head.  
   
   
       24 . The method of  claim 21 , further including the step of forming one or more vents in the housing.  
   
   
       25 . The method of  claim 21 , further including the step of forming a handle unitary with the housing.  
   
   
       26 . The method of  claim 21 , further including the step of coupling a power switch and lead to the electromagnet wire coil.  
   
   
       27 . The method of  claim 21 , wherein an electromagnet is contained within an electromagnet housing inside of the internal cavity of the housing.  
   
   
       28 . The method of  claim 27 , wherein the electromagnet housing includes an opening in communication with a vent in the housing.  
   
   
       29 . The method of  claim 28 , wherein the electromagnet housing has an open end that is closed by an end cap which defines an air volume in which a reciprocating component can move along the piston axis.  
   
   
       30 . The method of  claim 29 , wherein the end cap is dome-shaped and has an opening in communication with a vent in the housing.  
   
   
       31 . The method of  claim 21 , wherein the valve head includes a valve plate with an annular wall defining an air volume in which the cylinder is disposed.  
   
   
       32 . The method of  claim 31 , wherein the annular wall has an opening in communication with a vent in the housing.