ly U-shaped in cross section and is connected to the
wooden slat 6 by means of rivets, bolts, or the like, as
indicated at 8. This mounting bracket is fastened to
the undersurface of the seat at a second point. An elon-
gated opening 30 is provided through the web portion of 5
metal rail 7 and is spaced slightly inwardly of the free
end thereof, the purpose of this arrangement being ex-
A supporting bracket or fitting 9 is fastened to the bot-
tom of seat 2 and is of substantially U-shaped cross sec- io
tion, as indicated in FIGURE 4. The upper leg or web
section 10 is connected with the seat plate by four screws
11, and this portion is provided with a depressed central
part which itself has an elongated opening 31. The paral-
lel legs 12 and 13 are connected together at their lower 15
free ends by means of a swivel pin 14 which serves to
support the back rest carrier. Bearing bushings IS and
16 of synthetic resin, as, for example, polyamide, are
arranged at the ends of the swivel pin 14. In the vicinity
of the swivel pin 14 which passes through the upstand- 20
ing legs of rail 7, the rail 7 is reinforced. The arrange-
ment is such that the connection between the back rest
carrier and the fitting is movable and the two parts may
be easily swiveled with respect to each other.
The seat 2 and the inwardly extending rail 7 of the back 25 rest carrier have a rubber cylindrical body 17 connected therebetween, this body being designed as a tensile stressresponsive resilient spring member between the back rest carrier and the seat. This rubber body is connected to the seat at a third point and resiliently and yieldably cushions the seat and back rest carrier with respect to each other, this third point being spaced from the second point, i.e., the point at which the back rest carrier is pivotally connected to the underside of the seat means, in a direction opposite to that which the first point, i.e., the point at which the shaft engages the seat means, is spaced from the second point. Rubber cylinder 17 is disposed with its axis extending substantially parallel to the axis of the supporting shaft and forms approximately a right angle with the seat surface. 40
Metal plates 18 and 19 are arranged at the ends of the rubber cylinder and are suitably attached as, for example, by vulcanization. A screw bolt 20 extends through the opening 30 of rail 7 and a screw bolt 21 extends through the opening 31 of the fitting 9; these bolts are attached 45 to the metal plates, so that the cylinder 17 as a whole is mounted to form a unitary arrangement. The screw bolts are provided with nuts 20a and 21a so that the back rest carrier and the seat are connected with each other in a detachable and adjustable manner. It is thus possible to ^ adjust the height or lift or rearward position of the back rest simply by displacing the rubber cylinder 17 along the openings 30 and 31.
The adjusting screw 22 adjusts the back rest carrier relative to the seat. This adjusting screw extends through ^5 the rail 7 of the back rest carrier which is provided with a recess 23 in this location. This adjusting screw is threaded into a dished supporting disk 24 which is connected with the seat. Displacing the adjusting screw in an axial position by rotating the screw will adjust the position of the back rest relative to the seat. Thus, the adjusting screw fulfills the function of the rigid stops used hitherto in known swivel chairs or swivel arm chairs by means of which the movement of the back plate relative to the seat is limited in both directions. The back rest is angularly displaceable with respect to the seat. By means of rotational action due to the weight of a reclining person, the back rest may be moved into the position illustrated in phantom lines 28 in FIGURE 1, in a manner f0 which is known per se.
The dish shape of the supporting disk 24 is such as to give it a lower central portion which is fastened to the supporting shaft 3. The peripheral edge 26 of disk 24 is screwed to the undersurface of the seat plate at 27. 75
The central portion of the supporting disk 24 is connected at 29 with the supporting shaft in such a manner that the seat may be swiveled about the shaft. In this manner, the general over-all design of the chair is simplified as compared to known chairs or arm chairs in which the seat carrier plate is placed as a flat plate on wooden ledges which, in turn, are screwed onto the seat. This novel design is simpler and requires less structural elements.
It will be understood that the above description of the present invention is susceptible to various modifications, changes, and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims. What is claimed is:
1. In a swivel chair, the combination which comprises: seat means; a back rest carrier; means pivotally connecting said carrier to the underside of said seat means; and resilient means disposed between said seat means and said back rest carrier for biasing said back rest carrier toward its rest position when it is moved from such position, the position of said resilient means being selectively adjustable toward and away from said connecting means for changing the amount of biasing of said resilient means.
2. In a swivel chair, the combination which comprises:
(a) an upright supporting shaft;
(b) seat means supported by said shaft, said shaft engaging said seat means at a first point thereof;
(c) a back rest carrier pivotally connected to the underside of said seat means at a second point thereof which
30 is spaced from said first point; and
(d) tensile stress-responsive resilient means interposed between said back rest carrier and said seat means and being connected to the latter at a third point thereof which is spaced from said second point in a direction opposite
35 to that which said first point is spaced from said second point, whereby said resilient means are placed under tensile stress when said back rest carrier is pivoted rearwardly, the position of said resilient means being selectively adjustable toward and away from said second point for changing the tensile stress under which said resilient means are placed for a given amount of movement of said back rest carrier.
3. The combination as defined in claim 2, wherein said carrier includes a member directed inwardly below said seat means, and said resilient means include a cylindrical body, metal plates vulcanized to the ends of said body, and threaded connections attaching said plates to said underside of said seat means and said top of said member.
4. The combination as defined in claim 2, wherein said back rest carrier includes a metal rail disposed substantially horizontally and a wooden slat disposed substantially vertically so that said rail and slat are connected at about right angles.
5. The combination as defined in claim 4, further comprising a bolt pivotally connecting said back rest carrier and said seat means, said rail being U-shaped in cross section and having legs with openings therein, the openings receiving the ends of said bolt, and said bolt being rigidly connected with said seat means.
6. The combination as defined in claim 5, further comprising bushings of synthetic resin in said openings and receiving the ends of said bolt.
7. The combination as defined in claim 5, wherein said seat means includes a U-shaped supporting bracket fastened to said underside of said seat means, said bolt being supported in the legs of said supporting bracket.
8. The combination as defined in claim 7, wherein said resilient means are disposed between the legs of said supporting bracket.
9. The combination as defined in claim 8, further comprising a fastening element on each end of said resilient means, and elongated openings in the web portions of said U-shaped rail and said supporting bracket through which said fastening elements displaceably extend.
10. The combination as defined in claim 9, wherein the