Fire escape – ladder – or scaffold – Unitary foldable – rigid scaffold or ladder – Collapsible ladder
Reexamination Certificate
2000-08-11
2002-09-03
Lev, Bruce A. (Department: 3634)
Fire escape, ladder, or scaffold
Unitary foldable, rigid scaffold or ladder
Collapsible ladder
C182S104000, C182S129000, C182S165000
Reexamination Certificate
active
06443261
ABSTRACT:
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates to a step stool, and particularly, to a folding step stool having legs that fold between an opened use position and a collapsed storage position. More particularly, the present invention relates to a folding step stool having a latch for locking the step stool in the opened use position.
Step stools are frequently used around homes and businesses. Step stools must provide stability for the user when in an opened position. Further, step stools will ideally collapse to assume a storage position.
Step stools having legs that fold to assume both an opened use position and a collapsed storage position are known. See, for example, U.S. Pat. No. 4,485,892 to Maloney et al., U.S. Pat. No. 5,722,507 to J. Kain, U.S. Pat. No. 5,937,968 to Gibson et al., U.S. Pat. No. 6,000,497 to Kain et al., and U.S. Pat. No. 6,026,933 to King et al., all of which are hereby incorporated by reference herewith.
According to the present invention, a step stool includes a frame having a front leg and a rear leg movable relative to the front leg. The step stool also includes a leg lock coupled to the frame and arranged to retain the rear leg in a fixed position relative to the front leg upon movement of the rear leg to an opened use position. The leg lock includes a button supported for movement on the rear leg and a button receiver coupled to the front leg. The button is movable to a locked position engaging the button receiver and a released position disengaging the button receiver.
In preferred embodiments, the leg lock includes a button housing coupled to an upper end of the rear leg and formed to include a chamber containing a spring-loaded button arranged to protrude from the chamber through an opening formed in the button housing. The button receiver includes a pair of plates mounted on the front leg to provide a space therebetween for receiving the button housing herein when the rear leg is moved to assume its opened use position.
One of the button receiver plates is formed to include an aperture located and sized to receive the protruding outer end of the spring-biased button therein to establish the locked position of the button after movement of the rear leg to assume its opened use position. To unlock the rear leg so that the foldable step stool can be collapsed, a user pushes the button into the chamber in the button housing and against the force generated by the button-biasing spring located in the button housing to move the button out of the aperture formed in the button receiver plate, thereby establishing the released position of the button. The step stool can now be folded to move the rear leg to a “collapsed” opsition alongside the front leg.
The leg lock further includes a leg link having one end pivotably coupled to the rear leg at a point just below the button housing and another end pivotably coupled to one of the button receiver plates. The button housing mounted on the upper end of the rear leg swings out and away from the button receiver mounted on the front leg after movement of the button to a released position disengaging the aperture formed in the button receiver and movement of the rear leg to the opened use position.
Additional features of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.
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Gibson William R.
Giner Enrique R.
Barnes & Thornburg
Cosco Management Inc.
Lev Bruce A.
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