Chairs and seats – Rocker-mounted – With means to limit or inhibit rocking motion
Reexamination Certificate
1998-04-07
2001-04-10
Barfield, Anthony D. (Department: 3636)
Chairs and seats
Rocker-mounted
With means to limit or inhibit rocking motion
C297S270200, C297S270300, C297S370000
Reexamination Certificate
active
06213551
ABSTRACT:
BACKGROUND OF THE INVENTION
a) Field of the Invention
This invention relates to a new or improved locking mechanism for chairs and to a chair incorporating such locking mechanism. The invention is particularly although not exclusively useful with rocking and gliding arm chairs.
b) Description of the Prior Art
Numerous chair mechanisms have been proposed over the years for providing a rocking motion or a rocking and gliding motion of the chair seat, and frequently such chairs include mechanisms for locking the chair seat in a desired position relative to the chair base. Mostly these mechanisms are of considerable complexity, see for example U.S. Pat. No. 5,527,095 Marshall et al and U.S. Pat. No. 3,904,240 Rogers et al. A relatively simple locking mechanism is shown in U.S. Pat. No. 3,836,532 Caldemeyer wherein an upstanding rod pivoted to the base has serrations in its rear edge which are engageable with a pin mounted in a bracket that is affixed to the chair seat portion. A cam that is operated by a lever at the side of the seat can be swung into a position to hold the serrated rod in engagement with the pin. However this mechanism is relatively flimsy and it is doubtful that it could provide adequate resistance to the high disengagement forces which could be imposed upon the locking mechanism.
The aim of the present invention is to provide an improved locking mechanism is through a comparatively simple structure provides a strong and reliable locking action, and furthermore is convenient and easy for the occupant of the chair to utilize.
SUMMARY OF THE INVENTION
The present invention provides a locking mechanism for a chair having a base for supporting the chair on a floor and a chair seat positioned generally above the base and supported for movement thereon by a linkage connection, the locking mechanism being operable to immobilize said chair seat relative to said base, said locking mechanism comprising: a pin for attachment to one of said base and said seat and an elongate rack for attachment to the other of said base and said seat, said rack defining an array of teeth spaced along its length and presented towards said pin, said rack in use extending generally in a direction of movement of said chair relative to said base and being of such length that throughout at least a major part of said movement, said pin lies in register with said array of teeth; and an actuating mechanism selectively operable to effect relative movement of said pin and said rack towards one another to engage said pin with a registering tooth of said rack and thus lock said seat with respect to said base.
The rack is preferably pivotally attached at one end to the seat, the second end of the rack being swingable by a linkage mechanism to pivot the rack into or out of engagement with the pin on the base. The operating mechanism preferably comprises a lever handle carried on a pin and connected to a pair of pivoted strut links which can be moved through operation of the lever from a folded retracted position to at over center extended position. In the extended position the rack is advanced towards the pin to engage the latter with one of its teeth.
The above described locking mechanism is suitable for inclusion in many forms of chairs, and is particularly suitable for use in the kind of chair known as a gliding and rocking chair. The mechanism preferably includes a pin of substantial diameter, e.g. greater than ¼ inch, and preferably about ½ inch, engageable in deep teeth of corresponding size in the rack, this engagement providing a sufficient bearing surface to effect a secure locking action. For large chairs, and in particular for wide seating furniture such as sofas, the locking mechanism can be duplicated at opposite sides of the furniture.
BRIEF DESCRIPTION OF THE DRAWINGS
REFERENCES:
patent: 108255 (1870-10-01), Gravitz
patent: 712743 (1902-11-01), Van Slyke
patent: 1043112 (1912-11-01), Kronheim et al.
patent: 1421260 (1922-06-01), Kurnick
patent: 1555689 (1925-09-01), Miller
patent: 2284571 (1942-05-01), Heller
patent: 2302387 (1942-11-01), Greeno et al.
patent: 3093409 (1963-06-01), Fletcher
patent: 3826532 (1974-07-01), Caldemeyer
patent: 3897104 (1975-07-01), Black
patent: 3904240 (1975-09-01), Rogers, Jr.
patent: 4092041 (1978-05-01), Landry
patent: 4123102 (1978-10-01), Landry
patent: 4154475 (1979-05-01), Shoemaker
patent: 4411468 (1983-10-01), Apissomian
patent: 4534591 (1985-08-01), Parker
patent: 4707025 (1987-11-01), Rogers, Jr.
patent: 4957302 (1990-09-01), Maxwell
patent: 5527095 (1996-06-01), Marshall
Bellefleur Pierre
Desnoyers Charles
Fontaine Éric
Barfield Anthony D.
Dutailier International Inc.
Ladas & Parry
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