Untitled record

Application filed September 3,1883. (No model.}

To all whom it may concerns

Be it known that Ϊ, Henry Parry, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of 5 Wisconsin, have invented certain new and useful Improvements in Tilting-Chairs; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to io which it appertains to make and use the same, reference being had to the accompanyingdrawings, and to letters or figures of reference marked thereon, which form a part of this specification.

My invention relates to improvements in tilting-chairs, and pertains to that class in which the seat oscillates upon pivotal points, audits backward movement is resisted by a tension-spring.

· My invention consists in the construction and arrangement of the device by which the lever purchase of the seat upon the tensionspring may be increased and diminished, whereby a spring of a given tension is adapt25 ed to a light or heavy person.

My invention is further explained by reference to the accompanying drawings, in which Figure 1 represents a side view of a chair provided therewith, and Fig. 2 repre30 sents a vertical section thereof disconnected from a chair.

Like parts are represented by the same reference-letters in both views.

A is the chair-seat. C is the supporting35 bracket, which is provided with four radial arms, D D D D, arranged at uniform distances apart, and rigidly attached to the seat at their respective ends by bolts or screws at E. F is the stool. G is the supporting-screw. To the 40 top of the supporting-screw G is rigidly attached a bracket, Η. I is the tension-spring. J are pivotal supporting-arms. K is the tension-adjusting lever. L is the adjustingscrew.

The bracket H is provided, with downwardzprojectinglugs M, to whicli the pivotal arms %./// J are attached by pivotal bolt'M, upon which bolt the seat is supported and oscillates. It is obvious that by thus attaching the lower 50 ends of the pivotal arms to the downward-projecting lugs M, beneath the upper surface of the bracket H, the shoulders O O, formed on the respective sides of said pivotal arms above said pivotal bolt N, are adapted to serve as stops to the seat in its backward and forward 55 movement, against which the seat is brought to rest at the extremity of such movement.

The lev er K is provided with hook P, which engages in recess Q of the bracket H, the bearings of said recess Q serving as a pivotal 60 point upon which the lever K turns when adjusting the tension-spring, as mentioned. The front end of the lever K is connected by said adjusting-screw L to the screw-lug R.

The screw L is provided with a hand-nut S. 65 As the hand-nut S is turned upward upon said screw, the front end of said lever K is drawn downward, whereby its rear end is thrown upward together with the front -end of tensionspring, which is attached thereto, thereby de- 70 creasing the lever purchase of the seat upon the spring, which has the effect to increase the resistance of the spring. By an inverse movement of the nut S the front end of the spring is brought nearer to the fulcrum or pivotal 75 point of the seat, which has the effect to diminish the resistance of the spring, whereby a spring of a given tension is adapted tp support a light or heavy person.