Adjustable scaffold

Claim 2

In an adjustable scaffold having a base and a movable ladder section, a locking device comprising a sleeve, a rod member rotatably carried in said sleeve and extending beyond an end of said sleeve, a dog attached to said rod member adjacent an end of said sleeve, a handle attached to said rod member adjacent and end thereof, said handle being angularly offset and longitudinally spaced from said dog, said dog being adapted to selectively engage a plurality of vertically spaced openings in the movable ladder section to lock said ladder section in a plurality of fixed positions.

Claim 3

A locking device as set forth in claim 1 with the addition of a second dog attached to said rod member adjacent the other end of said sleeve and a second handle attached to said rod member adjacent the other end of said rod, said second handle being angularly offset and longitudinally spaced from said dogs.

Claim 4

A locking device as set forth in claim 2 wherein said dogs are coplanar and said handles are coplanar.

Claim 5

A locking device as set forth in claim 2 wherein said handles are of sufficient weight to cause said dogs to successively engage said openings while the movable ladder section is being extended.

Claim 6

A locking device as set forth in claim 4 wherein said handles are normally in a position lower than said dogs and said handles are movable upwardly to remove said dogs from operative association with said openings in order to permit free movement of the movable ladder section.

Claim 7

An adjustable scaffold comprising, a base having a fixed ladder portion, a plurality of movable ladder sections interconnected to each other and to said base, said fixed ladder portion extending obliquely upwardly toward said movable ladder sections, a first cable and pulley assembly interconnecting said base and said movable ladder sections, a second cable and pulley assembly interconnecting said movable ladder sections and a counterweight, a guide mounted on said fixed ladder portion, a roller received in said guide, said roller being connected to said counterweight so as to guide movement of the counterweight in a path parallel to the fixed ladder portion and between said fixed ladder portion and said movable ladder sections during extension and retraction of the movable ladder sections.

Claim 8

An adjustable scaffold comprising, a base having a fixed ladder portion, a plurality of movable ladder sections interconnected to each other and to said base, said fixed ladder portion extending obliquely upwardly toward said movable ladder sections, a first cable and pulley assembly interconnecting said base and said movable ladder sections, a second cable and pulley assembly interconnecting said movable ladder sections and a counterweight, a guide mounted on said fixed ladder portion, a roller received in said guide, said roller being connected to said counterweight so as to guide movement of the counterweight in a path parallel to the fixed ladder portion and between said fixed ladder portion and said movable ladder sections during extension and retraction of the movable ladder sections.

Claim 9

The invention set forth in claim 6 wherein said guide extends along at least a substantial portion of the length of the fixed ladder portion.

Claim 10

The invention set forth in claim 6 with the addition of a second guide carried by the fixed ladder portion, a second roller received in said second guide, said second roller also being connected to said counterweight.