US2303428A - Metal scaffolding - Google Patents

Description

1942- N. 5. BLACK METAL SCAFFOLDING 2 Sheets-Sheet 1 Filed March 13, 1940 INVENTOR. fi/a 6T fi/QM u i in.

DeQ 1942- N. 5. BLACK 2,303,428

METAL SCAFFOLDING Filed March 13, 1940 2 Sheets-Sheet 2 'INVENTOR.

ATTO Y. l

Patented Dec. 1, 1942 UNlTED'STATEfi PATENT OFFICE.

2,303,428 METAL SCAFFOLDING Nolan s. Black, Detroit, Mich. Application March 13, 1940, Serial No. 323,758

8 Claims.

This invention relates to metal scaffolding of the type composed of a series of interchangeable elements which can be assembled in combinations which will meet the scaffolding requirements under a majority of all types of Working conditions. i I One object of this invention is to achieve great adaptability or flexibility with the use of a fewer number of structural elements, as distinguished from previous scaffolds of this general character.

Another object is to permit the independent assembly and disassembly of these elements, or in other words, to permit any one element to be placed in position or removed from such position without affecting the structural relationship of adjacent elements.

Incidental to this object is a further object, namely, to design these elements so that their interengagement depends to the greatest possible extent upon interlocking surfaces rather than machine elements which are easily lost and misplaced.

Another object is to produce a scaffold composed of a series of triangular sections, thereby incorporating in such scafiold the well-known rigidity and strength of the structural triangle.

A further object is to construct elements having low weight, so that they may be easily and safely assembled by one or two men, and at a cost which will favorably compare with that of non-permanent wooden scaffolds.

Other objects and advantages, of lesser importance, will appear after a study of the following description of the invention, as supplemented by reference to the accompanying drawings, in which:

Fig. 1 is an elevation of the essential elements of the scafi'old in assembled relation.

Fig. 2 is a plan view of the same.

Fig. 3.is a section taken along the line 33 of Fig. 1.

Fig. 4 is a section taken along the line 4-4 of Fig. 1.

Fig. 5 is a side view of a sleeve-like element adapted to retain the horizontal members in position.

Fig. 6 is a side view of a foot upn which the upright members rest.

Figs. 7 and 8 are views of different types of upright members or extensions thereto.

Fig. 9 is a plan view showing floor sections assembled in the scafiolding.

Fig. 10 is a section taken along the line 10-1 0 line 'Il--,ll 'of Fig. 9, both showing details of this floor construction.

Fig. 12 diagrammatically shows the manner in which the scaffold is assembled in order to have it conform to a curving wall.

Fig. 13 illustrates vthe manner in which the elements of the scaffolding may be assembled in an arch construction.

Fig. '14 is an elevation'showing the scaffolding elements assembled to form the base of a tower.

Fig. 15 is a plan View of the structure in Fig. 14.

Fig. 16 shows an alternate form of the manner in which horizontal elements may be assembled to the vertical members.

The scaffolding of the present invention is supported froma series of upright posts such as the post 2| or the post 22, an alternate form used whereit. isnecessary to compensate for unevenness of the ground upon which the scaffold is to be erected. Deferring for the present, the discussion of. the post 22, the post 2| is .constructed of a length of square tubing, to the lower end of which is welded a filler member 23, adapted to fit snugly within the foot or standard 24, shown inFig. 6, or the upper end of any other upright member such as the end of the member'ZB shown in Fig. 7. These posts are connected by a series of horizontal braces comprising the brace 2'! and two other similar braces 28 and Y29 of equal length but shorter than the brace 21, portions of these latter two braces being shown in dotted lines in Fig. 2; and the combination of these three braces is such that the resultant distances between the center lines of any three posts to which they are connected form a right angle isoceles triangle, in which the two shorter braces 28 and '29 are the legs and the brace 21 the hypotenuse. This constitutes the basic element of the scaffolding, although other combinations are possible according to the nature of the work to be done. Each brace consists of a pair of vertical tubular members connected and triangulated by the members 3| to a horizontal member 32,.and while the respective sizes of these members may be varied .within wide limits, the essential requirement and feature of the present construction is that each successive size of cross brace should bear to the next smaller size of brace the approximate relation of a hypotenuse of a right angle isosceles triangle, the legs of which are composed of such next smaller size of brace, or in other words, the length of each successive size of brace is substantially equal to the length of the next smaller of Fig. 9 and Fig. 11 is a section taken along the 5 size of brace divided by sin By keeping the sizes of the horizontal braces in this relation, a wide range of scaffold structures is obtained with a minimum number of elements of different sizes and it is also thus possible to use triangulated combinations of all sizes of elements in the same system of scaffolding, in constructing such scaffolding to the dictates of each particular structure.

The flexibility of the present type of scaffolding arises principally from the manner in which the braces are attached to the uprights. A circular plate 33 is welded to the post 2| approximately midway its ends and is provided with a series of holes 34 adapted to receive the lower ends of the tubular brace members 30. Another similar plate 35, having holes 36, is welded to a sleeve 3! which slips over the upper end of the post or upright which is provided, as can be seen from the uprights in Figs. 7 and 8, with a hole 38 and a slot 39, and in attaching this sleeve to the post a bolt 49 is inserted through the hole 4| in the sleeve and the slot 39 in the post, thereby permitting a limited vertical movement of the sleeve such that when in its upper position the plate 35 is not quite raised above the upper end of the tubular member 30 of the brace 21. When the sleeve is in this upper position, the brace, therefore, is still secured to the post 2|, but it can be readily detached therefrom by'simply lifting the lower end of the tubular member 30 out of engagement with the lower plate 33, and then by swinging this lower end so as to clear this plate, the brace can be lowered until the upper end of the tubular member is withdrawn from the upper plate 35. Thus, when a plurality of braces are attached to one upright by a pair of plates, any one of them may be removed without disturbing the structural relationship of the others, and likewise, an additional brace may be included without affecting those already in place. In order to facilitate the assembly of the horizontal and vertical members, and because of the fact that the horizontal braces are pivotally mounted between the fastening plates and thus free in a limited sense to rotate about the posts, a short channel section 63 is welded to the periphery of the upper plate 35 adjacent one of the holes therein to serve as'an index to prevent rotation and retain any brace which may be connected to the post, through this adjacent hole in the plate 35, in its normally correct position. As soon as the desired number of braces are in position, the sleeve "3''! may be locked in its lower position by inserting a bolt through the then aligned holes 42 and 3B in the sleeve and post respectively. When the vertical member is extended by the use of another similar post or either of the posts 26 and 43 shown in Fig. 7 and Fig. 8 respectively, such post will be secured in position by this same bolt passing through the holes 44 in the filler member '23 of such post.

These posts 26 and 43 are constructed so that their combined length is equal to that of the standard post 2 l, and therefore the two posts can be used in place of any one of the longer posts; with the added feature that thereby greater horizontal bracing can be obtained wherever needed by reason of the design of the post 43 which is also provided with a plate 33, attached at a point adjacent its lower end. This combination of posts is used in erecting the structure shown in Fig. 13.

The adjustable post 22 is composed of a large jack screw 46, having a collar 41 mounted at its midpoint, and provided with right and left hand threads extending either side of this collar. This jack screw is contained within the post which is divided into two sections 48 and 49, to the adjacent ends of which are attached jack screw nuts 59 and 5| which are engaged by the threaded portions of the jack screw so that when it is revolved by inserting a bar in the hole 52 of the collar 41 the sections 48 and 49 will either move apart or be brought together, depending upon the direction of rotation. If the jack screw is constructed of a length of suitable tubing rather than of solid stock, the total weight of the post is low enough so that it can easily be handled; and this method of providing vertical adjustment for any surface inequalities is superior to the separate jack members now in use because it secures a greater extent of adjustment and also performs the dual function of post and jack combined.

Floor sections may be provided in place of the loose boards ordinarily used in scaffolding as shown in Figs. 9 to 11. These floor sections are triangular in shape, conforming to the dimensions of the brace members, which, as shown in Fig. 9 and previously described, ordinarily consist of two braces 28 and 29 forming the legs of a right angle isoceles triangle with a third brace 2"! forming the hypotenuse thereof. The floor section 53 fits within this combination of braces and consists of the necessary number of boards 54, assembled in the form of a right angle triangle to the periphery of which is bolted a Z-bar 55. Fig. 10, which is a section taken across the diagonal brace 21 where two floor sections come together, shows that at this point these Z-bars 55 will straddle the brace 21 and form a channel around its upper portion, whereas on the outer braces 28 and 29 the Z-bar will cover only approximately half of the surface of the upper portion of the brace so that similar floor sections may be added as the scaffolding is expanded. By the use of floor sections of this type the strength, rigidity, and safety of the scaffolding is materially increased. 7

Figs. 12 to 15 give a few instances of the manner in which the few basic elements of the scaffolding of the present invention may be assembled, and exemplify the wide range of constructions that may be secured. Fig. 12 shows that when it is necessary to build a scaffold to conform to a curving wall or tank, adjacent braces 56 and 51 lying along the wall of the structure can be placed at an angle to each other instead of forming a straight line, by merely leaving out a connecting brace which would ordinarily be placed as, for example, between the posts 58 and 59 and rotating the brace 51 in relation to the post 60. In this manner, a structure having practically any curvature can be surrounded by scaffolding.

In erecting a scaffold it frequently becomes possible to extend the structure horizontally without the necessity of providing vertical supports to the ground at the junctions of each of the horizontal members, but at the same time retaining a comfortable factor of safety for the pr'evailing load conditions.

This arch or bridge construction is assembled by first securing these brace members 62 between the plates ll and 18 of the main vertical posts 19 and 89. Then, by inserting the filler members of posts 43, shown in Fig, 8, in the post section of the braces 62, the structure may be built upwardly by incorporating standard braces 81 and 82 and further outwardly by the use of additional braces 62. At the center of the arch, the abutting post sections 83 and 84 are secured together by means of bolts 85 extending through holes provided for this purpose. Various other combinations of braces may be used to vary the length of the space of this arch construction; and, of course, it is also possible to use the brace member 62 to form an outrigger or overhanging section of scaffolding which is extremely useful in situations where there are irregularities in the upper portions of the structure around which the scaffolding is being erected, which irregularities are not present at ground level.

The post 26, shown in Fig, '7, can be used as the uprights of a base portion of a tower, as shown in Figs. 14 and 15; namely, by securing horizontal braces thereto between the circular.

plate 6! of a foot and a sleeve 31, this plate 6| being provided with a series of holes similar to the holes in the other plates 33 and 35 previously described. If it is desired to have a readily movable tower casters 65 are attached to the lower end of the posts 28 by the same bolt which holds the foot 24 in position, In order to give maximum rigidity at the base of the tower the horizontal braces 66 which form the sides thereof are mounted in an'inverted position, which is possible in any assembly of these scafiold elements, so that their horizontal members 6 3 are positioned adjacent the floor or other surface upon which the tower rests, while the diagonal brace 6'! is assembled in its ordinary position to give a bracing effect across the top portion of the posts. The tower may then be built to the desired height by simply adding other elements of this scaffolding such as upright members 2! and suitable braces.

Although the method preferably used in assembling horizontal braces to a post employs the movable sleeve 37 which clamps the horizontal braces securely in position, it is possible, as shown in Fig. 16, to use fixed circular plates 68 and 69 which are welded to a post 10 in such positions that a clearance is provided between the lower surface of the upper plate 68 and the top of the horizontal member 12 of the brace, so that the vertical member H of such brace is at all times retained in position, but may be readily removed therefrom by moving such vertical member upward, outward and then downward. The brace member shown in this view functions as, and is termed a catwalk support, although it may also be used to advantage as the boom of a hoist for bringing material to the workmen on the scafi'old.

Modification of the elements disclosed herein is permissible without departing from the spirit of this invention, as defined by the following claims.

I claim:

1. A scafiold comprised of vertical posts of tubular construction and horizontal braces extending between said posts, said horizontal braces being composed of vertical members positioned adjacent said posts and connected to a horizontal member extending therebetween, and means for securing said horizontal braces to said vertical posts comprising a fixed plate mounted on said posts, said plateihaving holes therein adapted to receive. the lower ends -of said vertical members of said horizontal'braces, asimilar plate adapted to receive theupper ends of saidvertical mem bers,-said latter platebeing mounted for limited vertical-movement so that at the upperlimit-of such movement said horizontal brace may be' detached from said posts or attached thereto.

2. A scaffold comprised of vertical posts of tubular construction and horizontal braces ex-.

tending between said posts, said horizontal braces being composed of vertical member positioned adjacent said posts and connected to a horizontal member extending therebetween, and means for securing said horizontal braces to saidvertical posts comprising a fixed plate mounted on said posts, said plate having holes therein adapted to receive the lower. ends of said vertical members of said horizontal braces, a similar plate adapted to receive the upper ends of said vertical members, saidlatter plate being secured to a sleeve, said sleeve being mounted on said post so as to be vertically'movable with relation thereto, the upper extent of such movement being such that in this position said, horizontal brace'remainssecured to said vertical posts but may be readily removedtherefrom. I

3. A scaffold comprised of vertical posts 'of tubular: construction and horizontal braces extending between said posts, said horizontal braces being composed of vertical members positioned adjacent said posts and connected to a horizontal .member extending therebetween, and means for securing said horizontal braces to said vertical posts in triangular relationship comprising a fixed plate mounted on said posts, said plate being provided with a series of holes spaced about the center of said post adapted to receive the lower ends of said vertical members, a similar plate adapted to receive the upper ends of said vertical members, said latter plate being mounted for limited vertical movement so that at the upper limit of such movement said horizontal brace may be detached from said posts or attached thereto.

4. A scafiold comprised of vertical posts of tubular construction and horizontal braces extending between said posts, said horizontal braces being composed of vertical members positioned adjacent said posts and connected to a horizontal member extending therebetween, and means for securing said horizontal braces to said vertical posts comprising a fixed plate mounted on said posts, said plate having holes therein adapted to receive the lower ends of said vertical members of said horizontal braces, a similar plate adapted to receive the upper ends of said vertical members, said latter plate being mounted for limited vertical movement so that at the upper limit of such movement said horizontal brace may be detached from said posts or attached thereto, some of said posts being of fixed length, others of said posts being adjustable in length so that said horizontal braces will lie in the same plane independent of ground conditions, said adjustable posts comprising an outer casing, a jack screw contained within said casing, and means to rotate said jack screw whereby vertical movement will be imparted to said casing.

5. A scaffold comprised of vertical posts and horizontal braces extending between said posts, said horizontal braces being composed of a main horizontal member, vertical members connected to each end of said horizontal member so as to project above and below said horizontal member, the extent of such projection of said vertical members above said horizontal member being greater than the extent of such projection below said horizontal member and means for securing said horizontal braces to said vertical posts comprising spaced plates carried by said posts, said plates being provided with a series of holes adapted to receive the upper and lower ends of the vertical members of said horizontal braces. I

6. A scaffold structure comprised of vertical posts of tubular construction connected by a series of horizontal braces, characterized by said horizontal braces each being composed of a main horizontal member, and vertical members connected to each end of said horizontal member, spaced plates carried by said posts, said plates being provided with means for engaging the upper and lower ends of said vertical members of said form of horizontal braces, thereby securing such braces to said posts, a second form of horizontal braces each being composed of a main horizontal member, a similarvertical member connected to one end thereof and a tubular post section connected to the other end thereof, said second form of horizontal braces being similarly secured to said posts by the interengagement of the vertical members thereof with said spaced plates, and other posts carried and supported by said post section of said second form of horizontal braces, whereby an arch construction may be employed in'said scaffold structure.

'7. A system of scaifolding composed of vertical posts, a series of horizontal braces of a plurality of different lengths of predetermined relation-- ship wherein each next longer brac of said series bears the relationship to the next shorter brace of said series of sin 45 where a: is substantially equal to the length of said next shorter brace, said horizontal braces being composed of a main horizontal member, vertical members connected to each end of said horizontal member so as to project above and below said horizontal member, and spaced plates carried by said posts, said plates being provided with a series of holes adapted to receive the projecting upper and lower ends of the vertical members of said horizontal braces, whereby said posts of said system of scaffolding may be interconnected by suitable lengths of horizontal braces from said series.

8. A system of scaflolding composed of vertical posts, a series of horizontal braces of a plurality of different lengths of predetermined relationship wherein each next longer brace of said series bears the relationship to the next shorter brace of said series of sin 45 where a: is substantially equal to the length of said next shorter brace, and means whereby said horizontal braces may be independently detachably connected to said vertical posts in polygonal relationships, comprising spaced plates carried by said posts, said horizontal braces being secured to said posts between a pair of said spaced plates.

NOLAN S. BLACK.

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