US2600199A

US2600199A - Extensible scaffold

Info

Publication number: US2600199A
Application number: US13402A
Authority: US
Inventors: William H Brewster
Original assignee: Individual
Current assignee: Individual
Priority date: 1948-03-06
Filing date: 1948-03-06
Publication date: 1952-06-10
Anticipated expiration: 1969-06-10

Description

June 10, 1952 w H BREWSTER 2,600,199

EXTENSIBLE SCAF'FOLD 1 m 3 m NH S H m NR \N m Q mu S N .r 2 QR 3 Nu m a u n \w m Q u 8 m8 3 Filed March 6, 1948 v Zhwentor muster- Will/21m H. B

J1me 1952 w. H. BREWSTER EXTENSIBLE SCAFFOLD Filed March 6, 1948 2 SHEETSSHEET 2 Bnventor Will/km b. Brew-fer Patented June 10, 1952 UNITED STATES PATENT OFFICE 1 Claim. 1

This invention relates to a scaffold and it is one object of the invention to provide a scaffold adapted to be suspended from an overhead support and of such construction that it may be adjusted longitudinally and thus provide a scaffold of various lengths.

Another object of the invention. is to provide a scaffold having an extensible platform mounted in a frame which consists of end walls and front and rear side walls, the side walls having upper and lower bars of telescoping construction so that extension of the scaffold will be permitted without weakening the scaffold.

Another object of the invention is to provide a scaffold having its side walls reinforced by braces which are longitudinally extensible and pivotally mounted at their ends so that they may extend diagonally and vary their angles as the scaffold is extended and contracted.

Another object of the invention is to provide a scaffold suspended from an overhead support by cables which are wound upon power-driven drums mounted under the platform of the scaffold, the cables being extended upwardly through guides mounted vertically at ends of the platform.

Another object of the invention is to provide a scaffold having a frame which may be formed of pipes coupled to each other, certain of the pipes forming standards mounted vertically at corners of the scaffold and provided with castors at their lower ends so that the scaffold may be easily rolled along the ground from one place to another.

The invention is illustrated in the accompanying drawings wherein:

Fig. 1 is a view looking at the lower side of the improved scaffold.

Fig. 2 is a top plan view of the scaffold.

Fig. 3 is a sectional view taken transversely through the scaffold along the line 33 of Figure 1.

Fig. 4 is a vertical sectional view taken longitudinally through one end portion of the scaffold along the line 4-4 of Figure 3.

This improved scaffold has a platform I formed of a plurality of

strips

2 and 3 disposed in side by side relation to each other and slidable longitudinally relative to each other so that the platform may be extended longitudinally when length of the scaffold is to be varied. The platform is mounted upon cross bars 4 which extend across the scaffold and "are carried by side bars 5 formed of pipe sections 6 and I, the pipes 6 being welded at their outer ends to vertically extending 2

corner posts

8 and 9 located at front and rear corners of the scaffold and the front posts having upper portions bent to'form bars I ll constituting upper rails or bars of end wall of the scaffold. Outer ends of the strips 3 are firmly secured to the cross bars 4 upon which they rest by bolts ll but the strips 2 and inner ends of the strips 3 are free from the cross bars upon which they rest so thatthe strips 3 may slide longitudinally along the strips 2 and thus allow the platform to be longitudinally adjusted. The rear corner posts have upper ends connected with each other by an extensible bar 12 consituting a top rail for the rear wall of the scaffold and the front corner posts are connected with each other by an extensible bar l3 constituting a top rail for the front Wall which is of less height than the rear wall, and referring to Figure 3 it will be seen that the top rail or bar I2 consists of telescoping pipe sections I2 and [2 and that similar telescoping pipe sections i3 and l3 form the rail or bar I 3. At the level of the platform the front posts are connected with the rear posts by tubular bars l4 welded at their ends to the posts. It will thus be seen that the scaffold has a frame formed of pipes or tubes so connected with each other that the frame will be very strong and may be adjusted longitudinally on the scaffold to increase its length when so desired. Castors l5 at lower ends of the corner posts allow the scaffold to be easily rolled along the ground from one place to another. Guards [6 and I! are provided for the side walls and consist of telescoping pipe sections or tubes having outer ends pivoted to collars I8 secured about the corner posts and their inner ends pivoted to collars l 9 secured about the inner tubes 7 of the side bars 5 between inner ends of the outer tubes 6 thereof. Since these guards are pivoted at their ends they may tilt as the frame for the scaffold is extended or retracted and assume straight line positions between the corner posts and centers of the side bars 5. In order to prevent tools from slipping off of the scaffold along front and rear sides thereof there have been provided sheets of wire screening 20 which extend vertically between the side bars 5 and the upper rails of the side walls in side by side relation to each other and are secured by collars 2|. Similar sheets of screening 20 are provided for end walls of the scaffold. The guards I6 and I! serve to prevent a workman from passing under the bars l2 and I3 if he should slip and roll or slide along the platform of the scaffold, thus reducing likelihood of a 3 workman falling from the scafiold. The guards l6 and I1 also serve as shields for the screens of the front and rear side walls and reduce likelihood of them being torn or accidentally knocked loose during use of the scafiold.

In order to suspend the scaffold in position for use there have been provided cables 22 which are wound upon drums 23 suspended from plates 24 mounted under the platform between certain of the cross bars '4. The plates also carry motors 25 for rotating the drums and by proper operation of the motors the drums may be selectively turned in directions to wind the cables thereon for raising the scaifold or to unwind the cables and lower the scaffold. The cables extend from the drums towards ends of the scaffold and have engagement with rollers 26 carried by brackets 21 which project inwardly from the cross bars l4. After the cables have been engaged with the rollers they are extended upwardly and through bushings 28 mounted vertically atupper ends of cable guides 29 which extend transverse- 1y of the scaffold and are of inverted V-shape formation and formed of angle metal bars having their upper ends welded together and their lower ends welded to ends of the side bars '5.

Having thus described the invention, what is claimed is:

A scaffold comprising an elongated horizontal frame having front and rear side bars and vertical front and rear corner posts and end bars extending between and rigidly secured to the front and rear corner posts, a rear rail extending between upper portions of the rear posts, a front rail extending between upper portions of the front posts, the side bars and the rails forming front and rear framing, said rails being formed of telescoping tubes having outer ends rigidly secured to the posts, said side bars being formed of tubular'end sections having outer ends rigidly secured to the posts and an intermediate section extending between and slidably mounted in the end sections, a platform in said frame extensible longitudinally with the frame, diagonal bars connecting upper ends of the front and rear posts and together therewith forming end framing for the scafiold, guards for the scaffold consisting of collars carried by upper portions of said posts and by the intermediate sections of the side bars and diagonally disposed telescoping bars pivoted at their outer ends to the collars of the posts and at their inner ends being pivoted to the collars of the intermediate sections of the side bars, and screens extending vertically between the side bars and the said rails against outer surfaces thereof in side by side relation to each other with the guards extending diagonally across them and constituting reinforcements for the screens.

WILLIAM H. BREWSTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Great Britain 1.91 1