Infrared sensing lift chair

#Power operated lift chairs are useful for raising persons, especially those having impaired mobility, from a seated to a standing position. These chairs include a powered lift mechanism which raises and tilts the chair allowing a seated occupant to stand with a limited amount of exertion. Further, in a reverse mode, the seat may lower a user from a standing to a seated position. U.S. Pat. Nos. 4,007,960, 4,083,599, and 4,993,777 describe various known lift chairs.

#Lift chairs of the type known in the art typically include a base frame which rests on the floor, a mechanism attached to the base frame, an electric motor-driven actuator for motivating the mechanism, and a seating portion for receiving a user. When the lift chair is raised, a gap is formed between the seating portion and the base frame. This gap poses a risk to a pet, a small child, or an unwary adult that may wander between the seating portion and the base frame. Injury may be caused when the lift chair is adjusted from a raised to a lowered position causing the person or pet to be compressed between chair components.

#It is known to use ribbon sensing switches under a seating portion or on a base frame of a lift chair, whereby a foreign object under the seating portion may contact one of the sensing switches cutting power off to a mechanism actuator. This configuration may not provide an adequate solution to the problem of protecting humans or animals that move into a position beneath a lift chair. It is possible for a human or animal to avoid contact with the sensing switches and become injured by the moving mechanism, because it is impractical to provide such a ribbon sensing switch on every potentially dangerous portion of the lift chair. Further, since many types of sensing switches require contact with an object before motion of the mechanism can be stopped, a living being may become injured trying to escape the moving lift chair or become trapped after the motion of the mechanism is stopped.

#FIG. 1 is a rear perspective view of a lift chair according to a preferred embodiment of the present invention.

#FIG. 2 is a front perspective view of a reclining lift chair according to another preferred embodiment of the present invention.

#FIG. 3 is a rear perspective view of a lift chair according to yet another preferred embodiment of the present invention.

#Certain terminology is used in the following description for convenience only and is not considered limiting. Words such as “front”, “back”, “top” and “bottom” designate directions in the drawings to which reference is made. This terminology includes the words specifically noted above, derivatives thereof and words of similar import. Additionally, the terms “a” and “one” are defined as including one or more of the referenced item unless specifically noted.

#The preferred embodiments of the present invention are described below with reference to the drawing figures where like numerals represent like elements throughout.

#Referring to FIG. 1, an adjustable furnishing in the form of a lift chair 10 is shown. The lift chair 10 includes a base 12 which supports a plurality of linkages of a mechanism 14. Alternatively, the base 12 may be omitted, and the mechanism 14 may be mechanically fastened to a pre-existing structure. User support members are provided including a seat portion 16, a back rest portion 18, and preferably armrests 20 which are connected to the mechanism 14. The mechanism 14 is configured to adjust the support members from a lowered position, where the seat portion 16 is substantially horizontal relative to a surface on which the base 12 rests, to a raised position (as shown in FIG. 1), where the seat portion is elevated and angled.