Chairs and seats – Movable back – Tiltable
Patent
1981-03-04
1983-07-12
Lyddane, William E.
Chairs and seats
Movable back
Tiltable
16337, A47C 1027
Patent
active
043926860
DESCRIPTION:
BRIEF SUMMARY
The invention concerns a unit of seating furniture according to the preamble of claim 1. Such a seating convenience is known from DE-OS No. 23 35 586. Therein the support of the seat and the back rest are adjustable independently of the instantaneous position of the other part in different positions in relation to the supporting structure, said adjustment being continuous. The clamping of the butt straps to the base frame is effected by means of the clamping bolt and the lever in a manner wherein eccentric disks mounted on the lever act to press or clamp the butt straps and the support structure together. The above cited reference further shows a similar arrangement, wherein the clamping or pressing function is effected by means of two cam disks of the clamping bolt. The disadvantage therein consists of the fact that the actuating surfaces of the eccentric or cam disks become worn in the course of time and for this reason or as the result of inaccurate manufacturing processes, do not occupy their exact intended position. This may lead to the consequence that the force exerted by the eccentric or cam disks is no longer sufficient to obtain the pressing effect desired.
A similar chair is known from DE-AS No. 19 02 670. Therein butt straps of this type are locked together by means of a manual lever, which is pressured into the clamping or locking position by a spring stressedly mounted between a lever arm associated with it and the back rest.
A chair similar to the above described type is further known from DE-GM No. 7 239 551. Therein, plates or straps of the seat carrier are passed through a plurality of plates of the support structure. By means of a screw that may be rotated by means of a manual handle, the two sets of plates or straps are clamped together to secure the position of the chair attained. The set of plates of the support structure is further connected with the back rest. The seat and the back rest may thereby be adjusted in any angular position with respect to the support structure and secured in such a position. A disadvantage, however, is the handling of the adjusting and immobilizing mechanism by the operator. The latter is required to reach with one hand under the chair to grip the handle of the screw and rotate the latter until there is no longer a frictional connection between the said plates or straps. Subsequently, the adjustment desired must be effected and then the screw handle must again be rotated to immobilize the setting, until the necessary clamping force is attained. The operator therefore must perform in addition to the adjusting process itself two further functions (unscrewing and lock-screwing), each of which requires a certain amount of time. Furthermore, it is difficult for a person seated on the chair to perform such a screwing adjustment, blind, as it were.
It is the object of the invention to improve a seating convenience according to the preamble of claim 1 so that a structurally simple arrangement is provided, while avoiding the above described eccentric clamping and its disadvantages, which assures even in the case of potentially occurring dimensional inaccuracies of the parts involved, a secure fastening of the parts of the chair in the position desired.
The object of the invention is attained by the characteristics of claim 1. Even when the parts involved are worn or are inaccurate in their dimensions, this can easily be bridged by the path of displacement of the clamping bolt that is relatively long with respect to said inaccuracies and by the corresponding expansion of the spring, so that even in such cases a satisfactory clamping or blocking of the parts is obtained. In spite of this, the swivel path of the lever for the locking of the parts may be relatively short. A slight touching is sufficient.
The invention is applicable both to the adjustment of the back rest in relation to the seat carrier and to the adjustment of the seat carrier with respect to the support structure, wherein preferably both of the above mentioned adjustment of a chair are suitably provi
REFERENCES:
patent: 1597847 (1926-08-01), Walton
patent: 4018104 (1977-04-01), Bland et al.
patent: 4198094 (1980-04-01), Bjerknes
Lyddane William E.
Steifensand Sitzmobel- und Tischfabrik, Inh.
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