US-12622828-B2 - Mechanism for lifting seat

US12622828B2US 12622828 B2US12622828 B2US 12622828B2US-12622828-B2

Abstract

A mechanism for tilting a seat or support from horizontal to inclined or even vertical. The mechanism tilts a top frame relative to a lower frame including an actuator. The top frame is attached to the lower frame by first and second rigid connections rotatably mounted relative to both the top frame and the lower frame, the first rigid connection is rotatably mounted to the top frame at a first axis and to the lower frame at a second axis. The second rigid connection is rotatably mounted to the top frame at a third axis and to the lower frame at a fourth axis. The actuator is mounted rotatably to the top frame at a fifth axis and also the actuator is mounted rotatably to an arm at a sixth axis, the arm extends from the first axis and the arm rotates together with the first axis.

Inventors

Hans Balle CHRISTENSEN

Assignees

Global FabTech (Shanghai) Company Limited

Dates

Publication Date: 20260512
Application Date: 20230106
Priority Date: 20220107

Claims (9)

1 . A mechanism for tilting a top frame relative to a lower frame comprising: an actuator; a top frame is attached to a lower frame by a first rigid connection and a second rigid connection rotatably mounted relative to both the top frame and the lower frame, wherein the first rigid connection is rotatably mounted to the top frame at a first axis and to the lower frame at a second axis, and the second rigid connection is rotatably mounted to the top frame at a third axis and to the lower frame at a fourth axis; wherein the first axis and the third axis are stationary relative to the top frame and the second axis and the fourth axis are stationary relative to the lower frame; wherein in a longitudinal direction, the top frame comprises a first half part comprising a first end, and a second half part comprising a second end and upon activation of the actuator, the first end is raised above a level of the second end; wherein the actuator is mounted rotatably to the top frame at a fifth axis and also the actuator is mounted rotatably to an arm at a sixth axis, the arm extends from the first axis and the arm rotates together with the first axis.
2 . The mechanism according to claim 1 , wherein the actuator is connected to the arm extending radially from the first axis by a third rigid connection, the third rigid connection is rotatably mounted to the arm at the sixth axis and to the actuator at a seventh axis.
3 . The mechanism according to claim 1 , further comprising a third rigid connection connected rotatably to the top frame at a seventh axis and connected rotatably to the actuator at an eighth axis.
4 . The mechanism according to claim 1 , wherein the fifth axis is positioned in the first half part of the top frame close to the first end.
5 . The mechanism according to claim 1 , wherein the first axis and the third axis are positioned at the second half part of the top frame, and the third axis is positioned closer to the second end than the first axis.
6 . The mechanism according to claim 1 , wherein an angle α between a top surface of the top frame and a top surface of the lower frame varies between 0 and 90 degrees.
7 . A chair or a wheelchair comprising: a mechanism for tilting a top frame relative to a lower frame comprising: an actuator; a top frame attached to a lower frame by a first rigid connection and a second rigid connection rotatably mounted relative to both the top frame and the lower frame, wherein the first rigid connection is rotatably mounted to the top frame at a first axis and to the lower frame at a second axis, and the second rigid connection is rotatably mounted to the top frame at a third axis and to the lower frame at a fourth axis; wherein the first axis and the third axis are stationary relative to the top frame and the second axis and the fourth axis are stationary relative to the lower frame; wherein in a longitudinal direction, the top frame comprises a first half part comprising a first end, and a second half part comprising a second end and upon activation of the actuator, the first end is raised above a level of the second end; wherein the actuator is mounted rotatably to the top frame at a fifth axis and also the actuator is mounted rotatably to an arm at a sixth axis, the arm extends from the first axis and the arm rotates together with the first axis; and a back support which is connected to the top frame or to another part of the chair/wheelchair.
8 . The chair or a wheelchair according to claim 7 , wherein the first end is a front end of a seat of the chair/wheelchair and the second end is a rear end of the seat of the chair/wheelchair.
9 . The chair or a wheelchair according to claim 7 , wherein the top frame is inclined at least 45 degrees relative to horizontal and the back support is inclined at least 85 degrees to the top frame in a standard sitting position, and/or at least 110 degrees relative to the top frame in a relaxed position.

Description

This application is a national application based on Patent Cooperation Treaty Patent Application No. PCT/CN2023/071073, filed on Jan. 6, 2023, the entire contents of which are incorporated herein by reference. This application claims under 35 U.S.C. § 119(a) the benefit of the filing date of Danish Patent Application No. PA 202200013, filed on Jan. 7, 2022, the entire contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION Technical Field The invention relates to a mechanism for tilting a seat or support from horizontal to inclined or even vertical. The mechanism is suitable for use in e.g. a wheelchair. The invention relates to a mechanism used to prevent pressure ulcers on the buttocks. Pressure ulcers affect nearly all wheelchair users and are a major cost factor in the healthcare system. Pressure ulcers are difficult to prevent and challenging to treat. Classical treatment involves extended periods of bedrest, which is believed to cause further deterioration of the patient's general condition and may lead to formation of ulcers in new places and even to sepsis or other potentially lethal complications. DESCRIPTION OF RELATED ART On way of reducing the risk of pressure ulcers to wheelchair users is to tilt the seat of the wheelchair. When a user is sitting on a chair or in a wheelchair, the part of the body experiencing the largest pressure is tuber ischiadicum, also known as sit bones. When the seat is tilted together with the back support, the pressure area moves along the back of the user thereby providing a larger weight-bearing surface consequently reducing pressure on the tuber ischii. This concept is e.g. known from the Rea Dahlia 45 wheelchair from Invacare shown in the video: Rea Dahlia 45 (published 16 Dec. 2016). The tilting mechanism of this chair includes an actuator being attached to the base of the wheelchair and pushing upward. There are other tilting mechanisms providing raising of a seat end. GB2591807 A relates to a furniture platform lifting mechanism. The furniture platform lifting mechanism 10 comprises a base 12, first and second connecting arms 14, 16 with complimentarily engaging guide 20 and follower, and an actuator 30 moving the mechanism 10 between a lowered and raised condition by moving the arms 14, 16 and an associated platform relative to the base while maintaining the guide 20 and follower connection. The arms 14, 16 are releasably engageable with the base 12 and the associated platform. When the actuator 30 is activated, it causes the follower to lift and rotate the associated platform relative to the base 12. An end of the second arm 16 may move freely against the base 12 or associated platform. The mechanism 10 may be used as part of an adjustable chair or with a desktop. The actuator 30 is attached to the lower frame, and the document does not teach how to adapt the angle of inclination of the seat. SUMMARY OF THE INVENTION The present invention relates to a mechanism for tilting a seat or support from lowered e.g. approximately horizontal position, to an inclined or raised position, i.e. the angle of a seat or support relative to horizontal in respectively a raised and a lowered position is changed. The invention improves the possibilities for incorporating the mechanism in a chair or wheelchair as the mechanism is very compact and takes up relatively little space. In the lowered position the actuator is hidden between the frames of the mechanism. The purpose of the present invention is to provide an inclination of a seat or support for wheelchairs in order for the user of the chair/wheelchair achieve a good redistribution of pressure towards the seat and e.g. avoid pressure ulcers. Optimally, the user should be able to place the seat or support in an angle of at least 45 degrees to obtain adequate relieve. According to a first aspect, the invention relates to a mechanism for tilting a top frame (A) relative to a lower frame (B) including an actuator (H), the top frame (A) is attached to the lower frame (B) by at least two rigid connections (C, D), the first and second rigid connections (C, D) are rotatably mounted relative to both the top frame (A) and the lower frame (B), the first rigid connection (C) is rotatably mounted to the top frame (A) at a first axis (3) and to the lower frame (B) at a second axis (1), the second rigid connection (D) is rotatably mounted to the top frame (A) at a third axis (4) and to the lower frame (B) at a fourth axis (2), the first axis (3) and the third axis (4) are stationary relative to the top frame (A) and the second axis (1) and the fourth axis (2) are stationary relative to the lower frame (B), in a longitudinal direction the top frame (A) includes a first half part having a first end (9) and a second half part having a second end (10) and upon activation of the actuator (H) the first end (9) is raised above the level of the second end (10), wherein the actuator (H) is mounted rotatably to the top fr