Lift chair with horizontally maintained armrests
A powered lift chair comprises a frame, a backrest, left and right armrests, a seat, a footrest, and a pair of linear actuator mechanisms. A first one of the pair of linear actuator mechanisms is utilized to control the backrest of the chair, while the second one of the pair of linear actuator mechanisms is utilized to move the frame of the chair between a lowered position and an elevated position, as well as to move the seat of the chair between a substantially horizontal orientation and a tilted orientation such that the forward end portion of the seat is tilted downwardly while the rearward end portion of the seat is tilted upwardly, all while the left and right armrests are fixed in position and disposed within horizontal planes. Such compound movements of the chair and the seat will stably assist a person to be moved from a seated position to a standing position while the person is able to grasp and push downwardly upon the left and right armrests whereby the fixed armrests will effectively provide the person with stable platforms upon which the person can reliably, securely, and safely place his or her hands so as to assist himself or herself to move from the seated position to the standing position.
1. A powered lift chair for assisting a person, seated within said lift chair, to be moved from a seated position to a standing position, comprising:
a chair base;
a chair frame mounted upon said chair base;
a pair of laterally spaced armrests, defining left and right armrests, mounted upon said chair frame such that upper surface portions of said left and right armrests are disposed within substantially horizontally oriented planes;
a backrest;
a footrest;
a seat movable with respect to said left and right armrests;
a pair of oppositely disposed seat assemblies, upon which said seat is fixedly secured, pivotally connected to said pair of laterally spaced armrests whereby said pair of oppositely disposed seat assemblies can pivot with respect to said pair of laterally spaced armrests;
a linear actuator operatively connected to said chair base and to said pair of oppositely disposed seat assemblies such that as said lift chair is moved from a lowered position to an elevated position by said linear actuator, said pair of oppositely disposed seat assemblies, and said seat fixedly secured thereon, can pivot and tilt with respect to said pair of laterally spaced armrests such that said seat is moved from a substantially horizontal position to a tilted position at which a forward end portion of said seat is at a lower elevation than a rearward end portion of said seat, while said upper surface portions of said left and right armrests remain fixed within said substantially horizontally oriented planes so as to serve as stable platforms and thereby enable the person to grasp said horizontally oriented upper surface portions of said left and right armrests such that said horizontally oriented upper surface portions of said left and right armrests can securely and stably assist the person to move from the seated position to the standing position while said lift chair transitions from said lowered position to said elevated position and said seat transitions from said substantially horizontal position to said tilted position.
2. The lift chair as set forth in claim 1 , wherein:
said pair of oppositely disposed seat assemblies comprises a pair of oppositely disposed seat link assemblies pivotally connected to said pair of laterally spaced armrests, and a pair of seat base brackets fixedly connected to said pair of seat link assemblies and pivotally connected to said chair base.
3. The lift chair as set forth in claim 2 , wherein:
said linear actuator comprises a motor end operatively connected to said chair base, and a piston end operatively connected to said seat.
4. The lift chair as set forth in claim 3 , further comprising:
a pair of transition brackets pivotally mounted respectively upon said pair of seat base brackets; and
a synchronization bar having its opposite ends fixedly connected to said pair of transition brackets and operatively connected to said linear actuator such that when a piston of said linear actuator is extended, said synchronization bar will force said pair of transition brackets to pivotally move with respect to said pair of seat base brackets.
5. The lift chair as set forth in claim 4 , wherein:
each one of said pair of seat base brackets is provided with an arcuately shaped slot; and
each one of said pair of transition brackets has a pin extending into each one of said pair of arcuately shaped slots,
whereby as said piston of said linear actuator is extended, said transition brackets will be forced to pivot, and said pins of said transition brackets will traverse said arcuately shaped slots so as to force said seat base brackets and said seat link assemblies to pivot so as to, in turn, cause said seat to be tilted downwardly such that said forward end portion of said seat is at a lower elevation than said rearward end portion of said seat.
6. The lift chair as set forth in claim 2 , further comprising:
a cross-tube fixedly connecting said pair of seat base brackets together.
7. The lift chair as set forth in claim 1 , wherein each one of said pair of laterally spaced armrests comprises:
an armrest fixing plate;
an armrest mounting plate fixedly connected to said armrest fixing plate; and
an armrest support link fixedly attached at one end thereof to said armrest mounting plate, and pivotally attached to one of said pair of oppositely disposed seat link assemblies so as to permit said oppositely disposed seat link assemblies to pivot with respect to said pair of laterally spaced armrests when said lift chair is moved from said lowered position to said elevated position.
8. The lift chair as set forth in claim 7 , further comprising:
an anti-deformation tube fixedly connecting said pair of oppositely disposed armrest support links together.
9. The lift chair as set forth in claim 7 , wherein:
each one of said pair of seat base brackets is pivotally connected to said chair base by a pair of lift links; and
a straight link pivotally connects one of said pair of lift links to one of said pair of armrest support links.