Dental chair

• US 4,456,297 A
• Filed: 05/18/1981
• Issued: 06/26/1984
• Est. Priority Date: 05/16/1980
• Status: Expired due to Fees

• Current Assignee: Nalge Company
• Original Assignee: Sybron Corporation (Envista Holdings Corporation)
• Inventors: Lipp, Herbert, Pietschmann, Helmut
• Primary Examiner(s): Lyddane, William E.
• Application Number:
  US06/264,486
• Time in Patent Office: 1,135 Days
• Field of Search: 297/361, 297/316, 297/320, 297/321-324, 297/330, 297/83, 297/84-87
• US Class Current: 297/316
• CPC Class Codes: A47C 1/0242 by electric motors
• CPC Class Codes: A47C 1/0244 by fluid means
• CPC Class Codes: A47C 3/38 with additional seat or additional legs for varying height of seat
• CPC Class Codes: A61G 15/02 Chairs with means to adjust position of patient; Controls therefor

Abstract

A dental chair has its backrest connected to the seat by a scissor linkage arrangement which effects the moving together of the contiguous portions of the backrest and seat concurrently with movement of the backrest from an upright to a reclined position.

Claims

1. A dental chair including a seat, a backrest and mechanism pivotally connecting the backrest to the seat comprising:

(a) a first link having a first end jouraled to said seat;

(b) a second link having a first end journaled to said backrest, said links crossing and being pivotally connected intermediate their ends to form a scissor linkage;

(c) a rocker arm connecting the second end of said first link to said backrest to permit arcuate displacement of the second end of said first link relative to said backrest;

(d) a crank arm connecting the second end of said second link to said seat to effect arcuate displacement of the second end of said second link relative to said seat;

(e) said mechanism being operative when said crank arm is moved in the direction away from said backrest to pivot said backrest downwardly, and concurrently said scissor linkage being operative to move the first end of said second link toward the first end of said first link.

2. A dental chair including a seat, a backrest and mechanism pivotally connecting the backrest to the seat comprising:

(a) a first link having a first end journaled to said seat, and a second end journaled to a slide which is in turn slidably mounted to said backrest;

(b) a second link having a first end journaled to said backrest, said links crossing and being pivotally connected intermediate their ends to form a scissor linkage;

(c) a crank arm connecting the second end of said second link to said seat to effect arcuate displacement of the second end of said second link relative to said seat;

(d) said mechanism being operative when said crank arm is moved in the direction away from said backrest to pivot said backrest downwardly, and concurrently said scissor linkage being operative to move the first end of said second link toward the first end of said first link.

3. A dental chair including a seat, a backrest and mechanism pivotally connecting the backrest to the seat comprising:

(a) a first link having a first end journaled to said seat and a second end journaled to a slide which is in turn slidably mounted to said backrest;

(b) a second link having a first end journaled to said backrest and a second end journaled to a slide which is in turn slidably mounted and selectively lockable relative to said seat;

(c) said links crossing and being pivotally connected intermediate their ends to form a scissor linkage;

(d) said mechanism being operable, when said second link is unlocked and slidable relative to said seat, to pivot said backrest downwardly, and concurrently said scissor linkage being operative to move the first end of said second link toward the first end of said first link.