US2590617A - Scaffold for handling sheet material - Google Patents

Description

March 25, 1952 R. HENDERSON ET AL 2,590,617

SCAF'F'OLD FOR HANDLING SHEET MATERIAL 2 smmwsmzaw 1 Filed July 5, 1949 3 Fig. 6.

Q F Inventors A R1 Lee E. Henderson Alfred C. Seago 14;

Wye/way E M5 March 1952 L. R. HENDERSON ET AL 2,590,617

SCAFF'OLD FOR HANDLING SHEET MATERIAL Fi1e July 5, 1949 2 SI-IEETS-SHEET 2 Alfred 6.. Seago Patented Mar. 25, 1952 UNITED STATES ATENT' OFF ICE SGAFFOLD FOR HANDLING SHEET MATERIAL LeeR. Henderson, Kosmos, and Alfred C. Seago,

Yakima, Wash.

Application July 5, 1949, Serial No. 10335 1 2 Claims. (Cl. 30429) Our invention relates to improvements in scafmasterussfmjeuam and applying to ceilings iii'buil'dings plaster board, 'wau oam, and the'like. mamm ry object of our invention is to provide a scaffold for supporting horizontally the material to be applied and at substantially the height of the usual table for cutting or otherwise'treating the material, and which is operative easily by one man to lift the material in leyel position a distance considerably greater than the height of a table, whereby the material may be easily applied to ceilings of; various heights in dwellingsand'the like.

Another object is to provide a scaffold for the purpose above set forth which is not liable to get outof order, is safe to use, easy to move about ina building, and comparatively inexpensive to easem Otherand subordinate objects within the purview of our invention, together with the precise natureoi our improvements will be readily'understo'od when the succeeding description and claims are read with reference to the drawings accompanying and'forming a partof this specifi- Qa b M l i 'In said drawings:

Figurel is a view in perspective, partly broken away and shown in section, of a preferred embodimentbf our improved scaffold, with the platiormfully lowered; "Figure '2 is a view in vertical transverse section taken on the line 2 2 of Figure l and drawn to a'largeriscalewith the scaffold partly elevated; Figure 3 is a view similar to Figure 2 with the scaifold completely elevated; l

Figure 4; is a viewin transverse section taken in the vertical" plane of one of the extension post structures and drawn to a still larger scale with the'scafiolcl completely lowered; I

"F gures" is ay'ie'w in horizontal section taken on'the line 5 -5 of FigE're'Z and drawn to a larger ll. H Figure 6 is a similar view taken on the line 6- 6 of igure fl, and

"Figure '7 is'another similar view taken on the line 'l----? of Figure 4.

Referring to the drawings by numerals, our improved's'caffold comprisesfas shown, an elongated, substantially rectangular frame i including a pairbf horizontal end base bars I connected in H ldngitudinal center Qffiaid name by a cen te r bar 2. pair of corner posts 3"of'rectarigula'r crb ssfsection and of substantially the height'o'f the ilsual table legs rise from acn'basebar l at the; outer cornersthereof, upon opposite sides thereof.

of the center bar 2, and are suitably fixed to said bars I. Each pair'oi corner posts 3 isconnected at the upper ends thereof-by "a top cross-bar. 4 secured to the outer sides of the pair; as at5, and is additionally connected by anothercross-bar 6 similarly secured to the p'airfof corner posts, as at 1, intermediate the top bar 4 and base bar" I. A longitudinal fran'ieb ar 8 connects the top crossbars 4 at the't'op of the fr "-nie'in' the longitudinal centerof said frame. v

At each outlet the frame I is a pair of corner guide posts9 ofrefctangular cross-section and the same height as the corner pcsts's and which rise from the base bar's I"'iiitermediate the pair "61 corner posts 3' and extend al' figsrdetne ccrjne pc'st 3' contiguous to same 'in" slightly spaced rla'tibn thereto for a purpose resentryseenf'rhe'guise posts 9 are preferably half the width of the'cor ner posts 3 which'ar'e arranged edegwise to said guide posts, and'said guide posts 9 are secured in any suitable mannerto the base bars I and'to the cross-bars 4, as at H]. Casters fl 'supppa 'me base bars I so that the described irainemay be easily rolled from place 'to place;

" The frame l is' designedto support a lift 12 comprising a rectangular worksupporting" and elevating platform 13 surmounting 's'aid frame and. having bottom cross'beains" l4" suitably'secured thereto. Extension post structures" l5 are provided at the corners of the framer forelevating and lowering said platform I and which are arranged in pairs at the, ends of said frame Opposite e a r of o n r host 3 and guid posts 9 and alongside the same-at the inner sides The extension post structures 15 each comprise, as part thereof, a pair of relatively fixed'side-byside posts l6, l6, like the guidefposts'll, and pref e'rably of the same height, and which are secured together in slightly spaced apartparallel relation at the upper and lower ends thereof'byplatesfl'l, l8, overly'ing and suitably'securedto said ends, for instance, as shown in Figure' 7. The post [6 of each relatively fixed pair l6 I6 is slidablyniounted on the adjacent guide post 9 by an Ershaped strap metal guide [9' loosely straddling said post It at the top of said uidepo ta and fitting part way around the top of the guide post 3, and in betweensaid post 9 and the adjacent corneijpost if, said guide 19 being nailed to" said post Qfa's at 20, all asbest shownin Figure 5: 'A' slide 2 wire the guide s, as best showni j straddles the lower end'of the slidably ind ted postfl isnau d thereto, *atzz', said'slide'fitting' W te- 4 2 e d'i l'eetveei as was the adjacent corner post 3 for sliding on said post 9. A single post 23, like the relatively fixed pair of posts [6, and forming part of the extension post structure I5, is slidably mounted on the other post I6 of the relatively fixed pair alongside said post I6. For this purpose U-shaped strap metal slide 24 straddles the lower end of the single post 23 and is secured thereto by nails 25, said slide loosely fitting part way around said post I6 and in between the pair of posts I6, I6 to slide vertically on said post I6. A guide 26, like the slide 24 straddles the single post 23 and fits part way around the upper end of the post I6, like said slide 24, but is nailed to said post I6, as at 21. The platform I3 is mounted on the single posts 23 by means of studs 28 fixed in the cleats I4 and vertically slidable in top sockets 29 in said posts 23. Cushion springs 36 surround the studs 28 intermediate said platform I3 and said posts 23.

Means for extending the extension post structures I is provided comprising the following. A horizontal central shaft 3I is journaled at its ends in the frame I in the cross-bars 6 with a pair of cable winding reels 32 fast thereon intermediate the pairs of extension post structures I3 at opposite ends of said frame I A crank 33 is suitably journaled in one cross-bar 6 and connected by a speed-increasing sprocket and chain drive 34 to one end of said shaft 28. Pairs of cables 35 at opposite ends of the shaft 28 are suitably connected to the reels 32, respectively, for winding thereon and over pairs of pulleys 36 suitably mounted above the reels 32 on the crossbars 4. Each pair of cables 35 is extended downwardly from the pulleys 36 under pulleys 31 in the lower ends of the slidably mounted posts I6 of the pairs of extension post structures l5 at the adjacent end of the frame l From the pulleys 31, each pair of cables 35 extends upwardly over pulleys 38 in the upper ends of said posts I6 of said structures, and then downwardly to the lower ends of the single posts 23 of said structures, at which point said cables 35 are fixed to said single posts 23 in lower end notches 39 therein and by means of cross pins 46 in said posts 23. Suitable vertical grooves M, 42, 43 are provided in the posts l6, I6, 23 of the extension post structures I5 to accommodate the cables 35.

Slotted angle brackets M are detachably suspended on hooks 45 on the corner posts 3 for supporting, horizontally, side planks 66 on the frame I at a suitable height for use by workmen in positioning work on the lower platform I3 or for other use, as desired.

A suitable releasable pawl 41 for the sprocket and chain drive 34 may be provided for dogging said drive against reverse operation for a purpose presently seen.

Referring now to the operation of the described scaffold, when the platform I3 is lowered, the extension post structures K5 are contracted into the position shown in Figures 1 and 4, in which the pairs of relatively fixed posts I6, I6 and the single post 23 rest side-by-side on the base bars I. The platform I3 is then supported substantially ta'ble high for placing work, not shown, thereon. At this point it is explained that the weight of the lift I3 including the posts 23 is substantially the same as that of the relatively fixed pairs of posts I6, l6. To elevate the plat form I3, the crank 33 is operated in the proper direction to wind up the cables 36 which will thereby lift the extension post structures I5 as shown in Figure 2, the slides 2I sliding on the guide posts 9 until the fastened ends of the cables 35 are nearly opposite the pulleys 36. During this operation, the posts l6 slide vertically in the guides I9. As will be seen, during lifting of the extension post structures l5, the pairs of relative fixed posts I6, I6 and the single post 23 will be lifted in unison until the platform I3 is partly elevated fOr the reason that the weight of the lift I3 and posts 23 counterbalances the force required to lift the relatively fixed pairs of posts I6, l6. Further winding of the cables 35 will then lift the single posts 23, as shown in Figure 3, relative to and independently of the pairs of relatively fixed posts l6, I6 to further and completely lift the platform I3. In this independent lifting of the single posts 23, the slides 24 slide on the posts I6 and the single posts 23 slide in the guides 26 until the slides 24 abut said guides 26. As will be clear, the platform I3 may be lifted, as occasion may require, to elevate the same to ceilings of different heights. Upon releasing the pawls 41, the extension post structures I5 and platform I3 will return under the influence of gravity to lowered position.

The foregoing will, it is believed, suifice to impart a clear understanding of our invention, without further explanation.

Manifestly, the invention, as described, is susceptible of modification, without departing from the inventive concept, and right is herein reserved to such modifications as fall within the scope of the appended claims.

Having described the invention, what is claimed as new is:

1. In a scaffold for applying work to ceilings, a substantially rectangular frame, end guide posts at the corners of the frame, pairs of extension post structures at the ends of said frame comprising pairs of side-by-side relatively fixed spaced apart posts, and a single post associated with each pair of relatively fixed posts, means to mount one of the relatively fixed posts of each pair on each guide post for vertical sliding of the pairs of relatively fixed pairs on said guide posts, means to mount the single posts on the other posts of the relatively fixed pairs for vertical movement therewith and vertical sliding independently thereof comprising guides for the single posts straddling the same and fixed to said other posts, and slides straddling the single posts and said other posts and running in the spaces between the posts of the relatively fixed pairs of posts, a work-supporting platform carried by the single posts, and cable wind-up means operatively connected to said relatively fixed pairs of posts and said single posts to lift the same simultaneously and the single posts independently, said platform and single posts counterbalancing the force required to lift said relatively fixed pairs of posts, whereby the relatively fixed pairs of posts and the single posts will be lifted simultaneously and the single posts subsequently lifted independently with respect to said relatively fixed pairs.

2. In a, scaffold for applying work to ceilings, a substantially rectangular frame, end guide posts at the corners of the frame, pairs of extension post structures at the ends of said frame comprising pairs of side-by-side relatively fixed spaced apart posts, and a single post associated with each pair of relatively fixed posts, means to mount one of the relatively fixed posts of each pair on each guide post for vertical sliding of the pairs of relatively fixedpairs on said guide posts, means to mount the single posts on the other posts of the relatively fixed pairs for vertical movement therewith and vertical sliding independently thereof comprising guides for the single posts straddling the same and fixed to said other posts, and slides straddling the single posts and said other posts and running in the spaces between the posts of the relatively fixed pairs of posts, a work-supporting platform carried by'the single posts, and cable wind-up means operatively connected to said relatively fixed pairs of posts and said single posts to lift the same simultaneously and the single posts independently comprising cables connected at ends thereof to the lower ends of said single posts, and vertically spaced pulleys on the pairs of relatively fixed posts around which said cables are trained, said platform and single posts counterbalancing the force required to lift said relatively fixed pairs of posts,

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

UNITED STATES PATENTS Number Name Date 522,526 King July 3, 1894 1,332,011 Weinberg Feb. 24, 1920 1,639,962 Pfiffner Aug. 23, 1927 1,644,613 Royer Oct. 4, 1927 2,183,679 Hillis Dec. 19, 1939 2,285,901 Chenoweth June 9, 1942

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