Internal heating device for air valves

Claim 2

A pneumatic valve for use in pneumatic systems and operable under subfreezing temperature conditions comprising a valve body having a movable valve element for opening and closing said valve and a control device for actuating said movable valve element; a heating device including a mounting plate having a face adapted to be attached to a surface of said valve body, said mounting plate having a recess in said face, means connecting said plate to said valve body with said face and said surface in opposition one to the other; at least one electrical resistance heating element disposed in said recess and in contact with said valve body surface for conducting heat to said valve body, said heating element adapted to be coupled to a source of electric energy; insulating means disposed within said recess lining the walls thereof and surrounding the surface of said heating element remote from said valve body and the sides thereof for directing heat toward said valve body, said plate and said recess being elongated, said valve element comprising a spool, said electrical resistance heating element comprising a cylindrical probe, said probe being disposed longitudinally in said recess and extending parallel to the longitudinal axis of said spool.

Claim 3

The device of claim 1 including sealing means on the face of said plate surrounding said recess so that, when said plate is attached to the surface of said valve body, said sealing means seals said plate to said valve, said insulating means and said sealing means comprising an elongated pad of asbestos having a central depression for supporting said heating element in contact against said valve body, the edges of said pad extending outwardly over a portion of the face of said plate to form a gasket between said plate and said valve body.

Claim 4

A pneumatic valve for use in pneumatic systems and operable under subfreezing temperature conditions comprising a valve body having a movable valve element for opening and closing said valve and a control device for actuating said movable valve element; a heating device including a mounting plate having a face adapted to be attached to a surface of said valve body, said mounting plate having a recess in said face, means connecting said plate to said valve body with said face and said surface in opposition one to the other; at least one electrical resistance heating element disposed in said recess and in contact with said valve body surface for conducting heat to said valve body, said heating element adapted to be coupled to a source of electric energy; insulating means disposed within said recess lining the walls thereof and surrounding the surface of said heating element remote from said valve body and the sides thereof for directing heat toward said valve body, said plate being generally elongated and having a generally U-shaped cross-section with said recess being defined between the legs of the U-shaped plate, said heating element being elongated, said valve element comprising a spool extending generally parallel to the longitudinal axis of said recess, at least one mounting flange extending ouTwardly from said U-shaped plate for mounting said heating device on a support.

Claim 5

A pneumatic valve for use in pneumatic systems and operable under subfreezing temperature conditions comprising a valve body having a movable valve element for opening and closing said valve and a control device for actuating said movable valve element; a heating device including a mounting plate having a face adapted to be attached to a surface of said valve body, said mounting plate having a recess in said face, means connecting said plate to said valve body with said face and said surface in opposition one to the other; at least one electrical resistance heating element disposed in said recess and in contact with said valve body surface for conducting heat to said valve body, said heating element adapted to be coupled to a source of electric energy; insulating means disposed within said recess lining the walls thereof and surrounding the surface of said heating element remote from said valve body and the sides thereof for directing heat toward said valve body, said plate being generally elongated and having a generally U-shaped cross-section with said recess being defined between the legs of the U-shaped plate, said heating element being elongated, said valve element comprising a spool extending generally parallel to the longitudinal axis of said recess, at least one mounting flange extending ouTwardly from said U-shaped plate for mounting said heating device on a support.

Claim 6

A pneumatic valve for use in pneumatic systems and operable under subfreezing temperature conditions comprising a valve body having a movable valve element for opening and closing said valve and a control device for actuating said movable valve element; a heating device including a mounting plate having a face adapted to be attached to a surface of said valve body, said mounting plate having a recess in said face, means connecting said plate to said valve body with said face and said surface in opposition one to the other; at least one electrical resistance heating element disposed in said recess and in contact with said valve body surface for conducting heat to said valve body, said heating element adapted to be coupled to a source of electric energy; insulating means disposed within said recess lining the walls thereof and surrounding the surface of said heating element remote from said valve body and the sides thereof for directing heat toward said valve body, said insulating means comprising an elongated pad of asbestos having a central depression for supporting said heating element and upwardly extending sides, the sides adapted to project outwardly beyond at least a portion of said plate face to form a seal between said plate and said valve body.

Claim 7

A pneumatic valve for use in pneumatic systems and operable under subfreezing temperature conditions comprising a valve body having a movable valve element for opening and closing said valve and a control device for actuating said movable valve element; a heating device including a mounting plate having a face adapted to be attached to a surface of said valve body, said mounting plate having a recess in said face, means connecting said plate to said valve body with said face and said surface in opposition one to the other; at least one electrical resistance heating element disposed in said recess and in contact with said valve body surface for conducting heat to said valve body, said heating element adapted to be coupled to a source of electric energy; insulating means disposed within said recess lining the walls thereof and surrounding the surface of said heating element remote from said valve body and the sides thereof for directing heat toward said valve body, said insulating means comprising an elongated pad of asbestos having a central depression for supporting said heating element and upwardly extending sides, the sides adapted to project outwardly beyond at least a portion of said plate face to form a seal between said plate and said valve body.

Claim 8

The device of claim 4 including a recess in the surface of said valve body in opposition to the recess in said plate, said heating element and said insulating means being partly disposed in said surface recess.