US 5,620,272 AGranted

Adjustable joint assembly for ladder sections

OwnerChim-Yuem Shenginventor

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Abstract

The angle between adjacent ladder sections may be adjusted by a joint assembly having two base plates secured to the sections, wherein a locking rod extending through one base plate is selectively engageable within one of plural blind holes in the other base plate to maintain the base plates and sections at a desired angle. A locating plate maintains the locking rod in an unlocked position to permit the angle between the plates and sections to be adjusted by a single user.

Claims1

Dependent claims

An adjustable joint assembly for ladder sections comprising:

a) a pivot shaft;
b) a first base plate and a second base plate pivotally mounted on the pivot shaft, the first base plate including a plurality of eccentric blind holes formed therein and the second base plate including an eccentric hole formed therethrough;
c) a locking rod having a retaining slot formed therein, the locking rod extending through the eccentric hole of the second base plate for selective engagement with any one of the plurality of blind holes of the first base plate for maintaining the second base plate at a desired angle relative to the first base plate;
d) a lever pivotally mounted to the pivot shaft and the locking rod, the lever being disposable between a locked position wherein the locking rod engages a blind hole of the first base plate for maintaining the second base plate at the desired angle relative to the first base plate and an unlocked position wherein the locking rod is disengaged from the blind hole to permit the second base plate to be pivoted relative to the first base plate;
e) a locating plate carried by the pivot shaft, the locating plate including a mounting hole having a peripheral edge, a finger strip for manual engagement by a user and a flange adjacent the mounting hole, the locating rod being loosely coupled to the locating plate through the mounting hole;
f) a torsional spring including a first end and a second end, the first end being disposed in engagement with pivot shaft and the second end being disposed in engagement with the flange of the locating plate for biasing the peripheral edge of the mounting hole against the locating rod;
and
g) whereby when the lever is disposed in the unlocked position, the peripheral edge of the mounting hole engages the retaining slot of the locating rod to maintain the lever in the unlocked position until manual engagement of the finger strip by the user to release the peripheral edge of the mounting hole from the retaining slot after adjustment of the desired angle between the base plates has been accomplished.

5 more elements

Dependencies are inferred from the claim text.

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Abstract

An adjustable joint assembly for ladder sections comprising:

a) a pivot shaft;
b) a first base plate and a second base plate pivotally mounted on the pivot shaft, the first base plate including a plurality of eccentric blind holes formed therein and the second base plate including an eccentric hole formed therethrough;
c) a locking rod having a retaining slot formed therein, the locking rod extending through the eccentric hole of the second base plate for selective engagement with any one of the plurality of blind holes of the first base plate for maintaining the second base plate at a desired angle relative to the first base plate;
d) a lever pivotally mounted to the pivot shaft and the locking rod, the lever being disposable between a locked position wherein the locking rod engages a blind hole of the first base plate for maintaining the second base plate at the desired angle relative to the first base plate and an unlocked position wherein the locking rod is disengaged from the blind hole to permit the second base plate to be pivoted relative to the first base plate;
e) a locating plate carried by the pivot shaft, the locating plate including a mounting hole having a peripheral edge, a finger strip for manual engagement by a user and a flange adjacent the mounting hole, the locating rod being loosely coupled to the locating plate through the mounting hole;
f) a torsional spring including a first end and a second end, the first end being disposed in engagement with pivot shaft and the second end being disposed in engagement with the flange of the locating plate for biasing the peripheral edge of the mounting hole against the locating rod;
and
g) whereby when the lever is disposed in the unlocked position, the peripheral edge of the mounting hole engages the retaining slot of the locating rod to maintain the lever in the unlocked position until manual engagement of the finger strip by the user to release the peripheral edge of the mounting hole from the retaining slot after adjustment of the desired angle between the base plates has been accomplished.

5 more elements