US 5,347,754 A · Position sensing apparatus

Abstract

Apparatus for use in determining the position of an object such as a sash door of a laboratory fume hood which has an elongated base member for attachment to the fume hood adjacent the sash doors. It includes an electrical switching means having an elongated electrical resistance means that provides a signal indicative of the position of a sash door, and an actuator means associated with each sash door adapted to move when the sash door is moved. The actuator means includes an actuator assembly positioned to operate the switching means at a switch location that varies as the sash door is moved. The actuator means includes a linkage means that permits accurate operation even though there is undesirable movement of the door relative to the base member.

Claims25

Dependent claims

Apparatus for sensing the position of at least one sash of a laboratory fume hood that is moveable along a track, said apparatus comprising:

an elongated base member adapted to be attached to the fume hood adjacent and parallel to one direction of possible movement of at least one of the sash doors;
an electrical switching means having an elongated electrical resistance means with a predetermined resistance value per unit length attached to said base member;
actuator means associated with said one sash door and being adapted to move when said sash door is moved, said actuator means including an actuator assembly positioned to operate said switching means at a switch location that varies along the length of the resistance means as said sash door is moved;
said actuator assembly being coupled to said base member and adapted to move relative thereto, said actuator means including a linkage means that extends to said sash door and attachment means for attaching said linkage means to said sash door.

1 more element

Apparatus for use with a position sensing system which includes an electrical switching means having an elongated electrical resistance means that generates a position generating electrical signal for a structure that is moveable along a predetermined path, said apparatus comprising:

an elongated base member for attachment adjacent the structure and said path, said base member having a bottom portion and spaced apart transverse side portions;
actuator means associated with and being adapted to move when said structure is moved, said actuator means including an actuator assembly positioned to operate said switching means at a switch location that varies along the length of the resistance means as said structure is moved;
said actuator assembly being connected to be retained by said base member and moveable relative to said base member, said actuator means including a linkage means that extends to and is attached to said structure.

Dependencies are inferred from the claim text.

Position sensing apparatus

Life of this patent

Position sensing apparatus

Life of this patent

Abstract

Claims25