Collapsible scaffold

Claim 2

A scaffold structure comprising: a base structure; a base shaft having opposite end portions secured to thE base structure; elongated boom means having opposite end portions, one end portion of said boom members being pivotally connected to said base structure; means for pivotally elevating and lowering the elongated boom means on said base structure; a work platform shaft having opposite end portions, rotatingly secured to the end portion of said boom means opposite the end portion thereof pivotally connected to said base structure; a horizontally extending work platform having an upper and lower side portion, the lower side portion thereof being secured to the work platform shaft such that rotation of the work platform shaft rotates the work platform; and means interconnecting the base shaft and the work platform shaft to transmit the movement of the base shaft in relation to said boom means, as the elongated boom means is elevated and lowered, to the work platform shaft, thereby rotating the work platform and maintaining the horizontal orientation of the work platform as the elongated boom members are elevated and lowered.

Claim 3

The scaffold structure of claim 1 wherein the means for elevating and lowering the elongated boom means is defined further to include: extensible piston and cylinder means connected between the base structure and said elongated boom means to provide power for elevating and lowering said boom means; means for supplying power fluid to said piston and cylinder means mounted on the base structure.

Claim 4

The scaffold structure of claim 1 wherein said base and said work platform shaft are substantially parallel.

Claim 5

The scaffold structure of claim 1 wherein the means interconnecting the base shaft and the work platform shaft is defined further to include: a pair of beveled gears, one beveled gear secured to the work platform shaft and the other beveled gear secured to the base shaft; a pair of beveled pinion gears, each beveled pinion gear sized and disposed to meshingly engage one of the beveled gears respectively; and a pinion shaft means having opposite ends, one end of the pinion shaft means being secured to one of the beveled pinion gears and the opposite end of the pinion shaft means being secured to the other beveled pinion gear.

Claim 6

The scaffold structure of claim 1 wherein said boom means includes two substantially parallel boom members and wherein each boom member is defined further to include: a stationary channel member connected at one end thereof to the base shaft; a sliding channel member having one end thereof connected to the work platform shaft, and the opposite end thereof slidingly disposed in the stationary channel member; and means to slidingly extend the sliding channel member from the respective stationary channel member, thereby further extending the height of the work platform.

Claim 7

The scaffold structure of claim 5 wherein the means to extend each sliding channel member from each stationary channel member, respectively, includes: a transverse member secured between the sliding channel members; auxiliary extensible piston and cylinder means connected between the base structure and the transverse member to provide power for extending and retracting each sliding channel member with respect to each respective stationary channel members, simultaneously; and means for supplying power fluid to said auxiliary piston and cylinder means mounted on the base structure.

Claim 8

The scaffold structure of claim 5 wherein the means interconnecting the base shaft and the work platform shaft include: a pair of beveled gears, one beveled gear secured to the work platform shaft and the other beveled gear secured to the base shaft; a pair of beveled pinion gears, each beveled pinion gear sized and disposed to meshingly engage one of the beveled gears; respectively; and a first pinion shaft having opposite ends, one end being secured to the beveled pinion gear meshingly engaging the beveled gear secured to the base shaft; a second pinion shaft having opposite ends, one end slidingly splined on the end of the first pinion shaft opposite the end secured to the beveled pinion gear, and the opposite end of said second pinion shaft being secured to the beveled pinion gear meshingly engaging the beveled gear secured to the work platform shaft.

Claim 9

The scaffold structure of claim 7 wherein said first pinion shaft has a bore of rectangularly shaped cross section extending a distance therethrough from the end of the first pinion shaft opposite the end secured to the beveled pinion gear, and wherein said second pinion shaft is slidingly disposed in said bore and has a cross section sized to matingly and slidingly fit in said bore.

Claim 10

The scaffold structure of claim 1 wherein the horizontally extending work platform includes: a generally rectangularly shaped base frame having opposite sides, secured on one side thereof to the work platform shaft; a pair of side guard fences generally disposed on one side of the base frame opposite the sides secured to the work platform shaft, extending generally perpendicular to the base frame, in one position thereof, and each side guard fence being pivotally secured to one side of said base frame in such a manner that when each side guard fence is pivoted to a position generally parallel to said base frame, a gap exist between each side guard fence and said base frame; a pair of gate members secured to the opposite ends of each side guard fence, each gate member being sized such that one of said gate members secured to each side guard fence can be pivoted to a position generally adjacent and parallel the respective side guard fence, and the other of said gate members on the same side guard fence gate members secured to each side guard fence can be pivoted to a position generally adjacent and parallel the respective side guard fence, and the other of said gate members on the same side guard fence as said one gate member can be pivoted to a position generally adjacent said one gate member and such that, in this position, each pair of gate members generally occupy the gap between each respective side guard fence and the base frame when each side guard fence is pivoted to a position generally parallel to said base frame.

Claim 11

A scaffold structure as defined in claim 1 and further characterized to include means for changing the length of said boom means.

Claim 12

A scaffold structure as defined in claim 10 wherein said boom means includes a lower portion; an upper portion slidingly engaging the lower portion for coplanar extension and retraction relative thereto; and wherein said means for changing the length of said boom means comprises a piston and cylinder means for extending said upper portion relative to said lower portion.

Claim 13

A scaffold structure as defined in claim 10 wherein the means interconnecting the base shaft and the work platform shaft is defined further to include: first gear means on the base shaft; second gear means on the work platform shaft; third gear means sized and disposed to meshingly engage the first gear means; fourth gear means sized and disposed to meshingly engage the second gear means; and shaft means having opposite ends, one end of the shaft means being secured to the third gear means and the opposite end of the shaft means being secured to the fourth gear means, thereby transmitting the rotational movement of the first gear means to the second gear means.

Claim 14

A scaffold structure of claim 10 defined further to include: extensible ladder means connected between the base structure and the work platform, adapted to extend and retract as the length of the boom means is changed.

Claim 15

The scaffold structure of claim 10 wherein the work platform is further defined to include: a base frame; a pair of horizontally spaced side guard fences pivotally mounted on opposite sides of the base frame and extending upwardly therefrom in one position thereof; and a Plurality of gate members pivotally connected to the side guard fences and forming a rectangularly shaped enclosure therewith, said side guard fences and gate members being foldable to a horizontally extending superimposed position over said base frame.

Claim 16

The scaffold structure of claim 10 defined further to include: a ladder means connected between the base structure and the work platform and adapted to move up and down the boom assembly as the length of the boom assembly is changed.