Thermoplastic bellows and method of forming the same
AssigneeOsmonics, Inc.
InventorPatrick H. Murphy
Life of this patent
Estimating the term…
Abstract
A bellows for use in fluid control devices includes a head, a shoulder, a blind hole extending from an opening in the shoulder to the head, and a hollow compressible neck between the head and the shoulder, through which the blind hole extends. The neck includes a thin-walled, circumferential band located between the shoulder and the head. The bellows is formed by forming, in a body of thermoplastic material, an inner bore having an inner diameter. Next, at least one thin-walled circumferential band is formed between the head and the shoulder. Finally, the body is deformed to cause each circumferential band to bow.
Claims19
A method of forming a bellows, the method comprising:
- forming in a body of thermoplastic material having a head and a shoulder, an inner bore having an inner diameter;
- forming at least one thin-walled circumferential band in one circumferential surface between the head and the shoulder;
- forming an undercut into the shoulder where the shoulder meets the band, whereby the undercut reduces strain in the band when deforming the body;
- and
- deforming the body to cause each band to bow.
A method of forming a bellows, the method comprising:
- forming in a body of thermosplastic material having a head and a shoulder, an inner bore having an inner diameter;
- forming at least one thin-walled circumferential band in one circumferential surface between the head and the shoulder;
- and
- applying fluid within the bore to cause outward bowing of each circumferential band.
A bellows comprising:
- a head;
- a shoulder;
- a blind hole extending from an opening in the shoulder to the head;
- a compressible neck, between the head and the shoulder, through which the blind hole extends, the neck including at least one thin-walled circumferential band located in one circumferential surface between the head and the shoulder;
- and
- an undercut into the shoulder where the shoulder meets the band, whereby the undercut reduces strain in the band when the neck is compressed.
A fluid control device comprising:
- a housing including a seat for blocking the flow of fluid through the fluid control device;
- a first integral thermoplastic bellows which includes:
- a shoulder with a seal for engaging the housing;
- a head which is movable in an axial direction with respect to the shoulder;
- and
- a hollow compressible neck between the head and the shoulder, the neck including at least one thin-walled circumferential band which is bowed and is capable of changing its bow to allow the neck to change length in the axial direction;
- a second integral thermoplastic bellows which includes:
- a shoulder with a seal for engaging the housing;
- a head which is movable in an axial direction with respect to the shoulder;
- a hollow, compressible neck between the head and the shoulder, the neck including a thin-walled circumferential rib which is bowed and is capable of changing its bow to allow the neck to change length in the axial direction;
- a poppet captured between the first bellows and the second bellows such that when axial force is applied to the head of the first bellows, the first bellows is compressed to move the poppet to permit fluid flow between the poppet and the seat while the poppet moves the head of the second bellows to expand the second bellows;
- and
- means for applying axial force to the head to cause the head to move in the axial direction with respect to the shoulder.
Dependencies are inferred from the claim text.