US2541556A - Scaffold - Google Patents

Description

T. G. STINSON Feb. 13, 1951 SCAF'FOLD 2 Sheets-Sheet 1 Filed Feb. 6, 1948 3nventor (Ittorneg T. G. STINSON Feb. 13, 1951 SCAFFOLD 2 Sheets-Sheet 2 Filed Feb. 6, 1948 Zmventor name 6. 629/230 BB ZV W (Ittomeg Patented Feb. 13, 1951 UNITED STATES PATENT OFFICE SCAFFOLD Truman G. Stinson, Spokane, Wash.

Application February 6, 1948, Serial No. 6,680

1 Claim. 1

This invention relates to scaffolds audit is one object of the invention to provide a scaffold suspended by cables coiled about drums which are mounted upon the scaffold and operated by electric motors, the motors operable individually or bothat the sametimeso that one end or the other of the scaffold may be raised or lowered to level the scaffold and the leveled scaffold raised or lowered along a wall or other structure to be painted, cleaned, or repaired.

Another object of the invention is to provide a scaffold wherein the motors are under control of a workman standing upon the scaffold and thus eliminate necessity of a ground crew to raise or lower the scaffold.

Another object of the invention is to provide a scaffold having a main section or platform and end sections which may be shifted longitudinally from a retracted position to an extended position when lengthening of the scaffold is desired.

Another object of the invention is to provide a scaffold having improved walls for preventing tools and other articles used by workmen from slipping off of the scaffold. I

The invention is illustrated in the accompanying drawings wherein:

Fig. 1 is a side elevation of the improved scaffold.

Fig. 2 is a view looking at one end of the scaffold.

Fig. 3 is a perspective View showing'a portion of the inner side Wall of the scaffold and a roller carried thereby.

Fig. 41s a top plan view of the scaffold.

Fig. 5 is a sectionalview taken through one end portion of the scaffold along the line 55 of Figure 4.

Fig. 6 is a perspective view of one end-portion of' the scaffold.

Fig. '7 is a wiring diagram.

This scaffold has a platform I which may be of any length and width desired and has side bars 2. which gradually decrease in depth towards their ends from a point midway the length of the platform. Floor boards 3, extend transversely of the platform with their ends fitting into grooves 4 bars midway the length of the scaffold and end portions of the sidebars carry cradles 8' which are formed of angle metal and serve as groundengaging shoeswhen the scaffold is resting upon the ground. The shoes are of duplicate con-' struction and each has side bars 9 and a cross bar ID, the cross bar being welded to inner ends of the side bars and having its end portions bent upwardly and forming arms I l which are secured to the side bars of the platform. The side bars 9 of the cradles have their outer end portions bent upwardly so that they arecurved. as shown in Figure 5, and from an inspection of this figure and Figure 1, it will be seen that when the scaffold is resting upon its wheels I the scaffold may be easily rolled along the ground and the upwardly curved outer portions of the cradleswill allow ends of the scafiold to readily move across uneven placesencountered. The scaffoldmay also be rocked upon the wheels and the ends of the scaffold tilted upwardly. when necessary.

Walls 52 and i3 extend along sides-of the scaffold and it. should be noted that the inner wall is lower than the outer wall so thatworkmen using the scaffold may readily reach a wall to be painted. These walls consist of horizontal rails l4 and I5 secured to upper ends of standards l6 and ll rising from the side rails of the platform I and in order to prevent tools from slipping off of the outer side edge of the platform screening [9V is secured to the rail 14 and the outer side bar of .the platform. Bars 18 extend diagonally between ends of the railsl l and I5 to support the inner. wall in a vertical position and the outer wallat an outward incline and these bracing bars also serve as rails for end walls of the scafiold which are provided with screening 19 toprevent toolsand oher articles from dropping off ends of the scaffold.

An extension 20 has been disclosed for one end of the scaffold but it will be understood that extensions may be provided for both ends of the scaffold. This extension has a floor 2! formed from a sheet of thick sheet metal. The sheet metal floor is formed with a longitudinally ex tending slot 22 and along opposite side edges of the sheet are' mounted angle metal strips 23 which fit under companion angle metal strips 24 mounted along the side bars 2 of the platform I. An outer end wall 25 consisting of a metal frame 26 carrying screening 21 is connected with the floor 2! by hinges 28 and in order to support this end wall in a raised position there have been provided braces 29 which extend diagonally between side edge portions of the floor and the frame 26 and are removably secured thereto. Threaded stems or bolts extend from upper corners of the end wall for engagement by bracing rods 3| which are removably connected with the side walls of the scaffold. Since the end extension or auxiliary scaffold section is releasably secured by the bracing rods 29 and 3| it may be slid to extended and retracted positions.

In order to suspend the scaffold from overhead supports there have been provided cables 32 having hooks 34 at their ends. These cables pass through bushings 35' at upper ends of yokes 35 which are of inverted V-shaped formation and mounted transversely of ends of the platform I. The cables pass through the slots 22 of the floor plates 2| and through openings in the platform I, and under the platform the cables are trained about pulleys 36 and extended longitudinally of the platform and wound about drums 3'! which are rotatably supported in the cradles =8. Each cable is wound about a drum at the opposite end of the platform from its guide pulley, and in order to rotate the drums and thereby cause raising or lowering of the scaffold there have been provided motors 38 carried by the cradles. A switch 39 is mounted at a convenient place upon the scaffold together with a second switch 40. The movable contact of the switch 39 is connected with one side of the battery 4| by a wire 42, the other side of the battery being connected with the movable contact of the switch 40 by a wire 43. Wires 44 and connect stationary contacts of the switch 49 with the motors and wires 46 and 41 extend from the motors to the stationary contacts of the switch 39. Other wires 48 and 49 lead from the motors, the wire 48 being cut into the wire 46 and the wire 49 being cut into the wire 41. Ordinarily the movable contact of the switch 40 is in position to connect the wire 43 with both of the wires 44 and 45 and the movable contact of switch 39 may then be moved to selectively close. a circuit through the motors by way of the wire 46 and the wire 41. When the circuit is closed by way of the wire 46 the wire is connected with one side of 4 each motor by the wires 46 and 48 and the motors will be turned in a direction to wind cable upon the drums and raise the scaffold. When the other stationary contact of the switch 39 is engaged by its movable contact the connection with the motors is by way of the wires 4! and 49 and the motors will rotate in an opposite direction. It will thus be seen that by proper manipulation of the switch 39 the drums may be rotated in one direction to wind the cables thereon and raise the scaffold or in an opposite direction to unwind the cables and lower the scaffold. By moving the movable contact of the switch 49 into position for engaging only one of its stationary contacts, only one motor will be operated and one end of the scaffold will be raised or lowered while its other end remains stationary. The scaffold may thus be leveled after it has been moved to a desired elevation or during such movement.

While the scafiold is being raised or lowered its side presented towards a wall is liable to scrape along the wall. In order to prevent damage to the wall there have been provided rollers 50. There have been shown two of the spacing rollers but it will be understood that additional rollers may be provided if so desired. These rollers are rotatably mounted between the arms 5! of the bearing brackets 52 which are mounted upon the rail 15 of the inner side wall 13 and are slidable along this rail to adjusted positions where they I are secured by pins 53 which are passed through openings in the brackets and into selected ones of the openings 54 formed vertically through the rail l5. The rollers may thus be moved to positions in which they will bear against portions of a wall of a building between window openings and roll along the wall without striking window sills as the scaffold is shifted vertically along the wall.

Having thus described the invention, what is claimed is: p

A scaffold comprising a platform having side rails and flooring carried thereby, cradles under end portions of said platform each having side bars and a cross bar secured thereto, end portions of the cross bar being bent upwardly and secured to the platform and outer end portions of the side bars being curved upwardly and secured to the platform, the side bars constituting runners, wheels under the side rails of the platform midway the length of the scaffold and extending downwardly from the platform below the plane of the cradles a distance adapting the wheels to rest upon ground and mount the scaffold for vertical tilting movement into and out of position for alternate engagement of the cradles with the ground, drums under end portions of said platform rotatably supported in said cradles, a motor carried by each cradle for turning the drum mounted thereon, suspension cables wound about said drums, and cable guides of inverted V-shape extending upwardly from end portions of the platform and disposed transversely thereof and having their upper ends located midway the width of the platform and formed with openings through which the cables slidably pass.

TRUMAN G. STINSON.

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

UNITED STATES PATENTS Number Name Date 284,308 Klein Sept. 4, 1883 760,239 Oursler May 17, 1904 903,478 Keil Nov. 10, 1908 929,680 Lott Aug. 3, 1909 984,063 Berg Feb. 14, 1911 1,000,738 Magnuson Aug. 15, 1911 1,113,509 Thrall Oct. 13, 1914 1,115,775 Bisboch Nov. 3, 1914 1,861,514 Bottoms July 28, 1931 2,007,294 Cischke July 9, 1935 2,112,837 Fisher Apr. 5, 1938 2,391,172 Leland Dec. 18, 1945 2,396,127 Riblet Mar. 5, 1946

Images