US2652967A - Multiplatform stepladder - Google Patents

Description

Sept. 22, 1953 c. F. HANSEN 2,652,967

MULTIPLATFORM STEPLADDER Filed Dec. 10, 1949 4 Sheets-Sheet 1 Sept. 22, 1953 c. F. HANSEN 2,652,967

MULTIPLATFORM STEIPLADDER Filed Dec. 10, 1949 4 Sheets-Sheet 2 big 7 I w F $2026.} avzaea/a p 1953 c. F. HANSEN 2,652,967

MULT I PLATFORM STEPLADDER Filed Dec. 10, 1949 4 Sheets-Sheet 3 Ceciewa Sept 22, 1953 c. F. HANSEN 2,652,967

MULTIPLATFORM STEPLADDER 4 Sheets-Sheet 4 Filed Dec. 10, 1949 Patented Sept. 22, 1953 MULTIPLATFORM STEPLADDER Cecil F. Hansen, Hastings, Mich., assignor to Craft-Belt Company, Hastings, Mich., a corporation of Michigan Application December 10, 1949, Serial No. 132,298

'7 Claims.

The present invention relates to improvements in stepladders and concerns itself particularly with stepladders of the type in which the treads or steps are of platform width so as to give full support to the users feet, and in which certain of the treads may be withdrawn from their nor mal alignment position in order to afford knee or shin clearance when standing on lower treads.

Conventional stepladders, that range in height from four to eight feet, and are designed for household utility purposes or for the accommodation of certain types of industrial, maintenance and construction services as heretofore known, have possessed limitations that have rendered ladders of this class in certain respects, less convenient and serviceable than need be. For example, the side members or flights to which conventional rungs have been permanently secured being necessarily of narrow width have dictated correspondingly narrow width to the rungs and have resulted in the practice of providing rungs which are uncomfortable, and lacking in support for adult footing. Where a ladder is required to be used over extended periods of time as for wall washing, painting, etc., the inadequacy of foot support is directly attributable to early fatigue and leg pains. Users are required to direct much of their attention to the maintenance of weight distribution and balance and in this way, such ladders have assessed a tribute of energy and concentration of mind.

On the other hand, where wide tread stepladders were constructed under heretofore known practices, the relative displacements required made the ladders necessarily of excessive span in order that uppermost rungs be adequately displaced from their next lowermost adjacent rungs. Even where certain displaceable rungs have been contemplated additional factors akin to diminution of safety and depletion of rigidity weighed against the utilitarian advantages which were gained.

It is now proposed within the contemplation of the present invention to teach a ladder construction which has the advantages of wide platform treads, uppermost ones of which may be bodily displaced so as to afford overlying clearance in respect to lower rungs without sacrificing the prime essentials of safety and rigidity but instead, contributing additionally to the traverse bracing reinforcement factors of basic ladder design.

A principal object of the present invention, therefore, is one of achieving a folding stepladder design which employs retractile treads of wide platform width and which may be folded and otherwise manipulated with ease and facility comparable to that of a conventional stepladder.

Another object of the present invention is to provide a multiple tread folding stepladder in which each tread is supported by a foldable cross bracing so as to afford generous rigidity and security of support while yet permitting the ladder to be instantly folded with simultaneous collapse of the cross bracing and whereby such manipulation can be managed with facility by a single operator.

With these and other objects in view, attention will now be directed to the accompanying drawings and to the hereinafter following detailed description, in both of which, like reference characters designate corresponding parts throughout, and in which:

Fig. 1 is a diminutive perspective view of a short height stepladder in which are embodied certain features of the present invention illustrating a multiple tread adaptation in which the uppermost treads are shown swung away so as to be out of utility position;

Fig. 2 is a perspective view of a taller stepladder in which are embodied certain of the features illustrated in Fig. 1 and in addition, certain supplementary features of particular importance to structures of greater height;

Fig. 3 is a side elevational view with portions broken away of a tall ladder of the type illustrated in Fig. 2;

Fig. 4 is a side sectional view of the upper portion of a stepladder such as that illustrated in Figs. 2 and 3;

Fig. 5 is an enlarged side elevational view of the ladder featured in the figures whose description is immediately preceding, showing various of the details in a stage or condition of partial collapse;

Fig. 6 is an enlarged sectional detailed view taken approximately on line 6-6 of Fig. 3;

Fig. 7 is an enlarged fragmentary sectional detailed View taken approximately on line 1-1 of Fig. 3;

Fig. 8 is an enlarged sectional detailed view taken approximately on line 8-8 of Fig. 3;

Fig. 9 is an enlarged detailed fragmentary view taken approximately on line 9-9 of Fig. 13;

Fig. 10 is an enlarged detailed fragmentary view taken approximately on line IB| 0 of Fig. 3;

Fig. 11 is a fragmentary side elevational view of the brace hinge construction with portions broken away to reveal interior details;

Fig. 12 is an enlarged side elevational view of one of the foldable tread structures;

Fig. 13 is a view similar to Fig. 12, showing the same elements with portions partially broken away in an initial stage of folding or collapse;

Fig. 14 is a detailed plan view partially in sec tion and is taken approximately on line I4l4 of Fig. 12; and

Fig. 15 is a side elevational view with portions broken away, showing the ladder structure featured in Figs. 1 and 2 fully folded and in condition for storage.

Attention is directed to the reference numerals l9 and 2|, Fig. l, which designate the frontal side brace or flights of a short height stepladder constructed in accordance with certain features of the present invention. In stepladder of the magnitude illustrated, a top platform 22 which is indicated as comprised of two slats, is bolted to a pair of hinging brackets 23 and 24 to which the side flights l9 and 2! are rigidly bolted as at 25 and to which a pair of rear flights 26 and 21 are pivotally bolted as at 28 so that the angle of the platform 22 remains fixed with respect to the forward or frontal flights I9 and 2| but this angle is made variable to the rearmost flights, depending on whether the ladder is open or collapsed as will become evident during the ensuing course of the description.

Since the principal details of this short stature embodiment are essentially similar to certain of those contained in the longer stature ladder, Fig. 2, attention will now be directed to the latter for particular description, it being sufficient to note the indicated comparisons and to observe that the bracing and platform details are the same as those characterized in the uppermost portion of the tall stature design.

The foremost or frontal flights 29 and iii in the taller structure are supplemented at their lowermost extremities by transverse ladder steps or rungs 32 to 35 of the conventional type consisting of relatively narrow width slats which may be held in shallow recessing on the interfaces of the flights 29 and 3| and secured by nethermost brace rods designated 38 after the manner of recognized practice in connection with conventional stepladders.

As with the case of the Fig. 1 embodiment, the flights 29 and 3| are bolted as at 31, see also Fig. 8, or riveted to a hinging channel 38 or bracket across the top of which there rest the floor slats 39 also riveted as at 4| but in this case, to the narrow edge surface 42 of the channel bracket 38. At 43 in respect to each of the channel brackets 38 are pivotally articulated the rearmost stiles or braces 44 and 45, the cross section of which may be somewhat narrower but preferably of the same thickness as the frontal corresponding element just described.

Beneath the top platform, which is comprised in this illustration of two slats 39 and spaced therefrom preferably at a distance corresponding to the usual distance between successive treads or steps, is a topmost foldable tread indicated as made up of two slats of floor board 46 and 41 shown folded in Fig. 2 and open in Figs. 3, 4 and 5, see also Fig. 6. These slats rest upon the horizontal flanges of a pair of angle metal bracebrackets indicated 48 and 49. Since the side elevational and sectional views are taken principally from the right side of the assembled product, bracket 48 will be more apparent throughout the several views and as best revealed in Fig. 5, this element will be observed to be pivoted at its forward end 5| in the frontal rail 29 and at 52 to its companion link bracket 53. The latter, in turn, is pivoted as at 54 to the rear stile 44. The

apertures of the companion elements 53 where they are pivoted at 54 are preferably elongated as at 55 for a purpose which will be better understood at a later period in the description. The construction of the corresponding elements, including foremost link brace 49 on the other side, is symmetrical and opposite to the details of description thus far discussed in connection with members 48 and 53.

The rearmost or non-displaceable slat 47 is riveted between the horizontal flanges of the al' ready described braces 48 and 49 and a pair of symmetrically opposite hinge brackets 55 and 51 (not visible). Each of these brackets is formed with a hinge ear 58 which aligns with a corresponding ear 59 formed in a generally similar bracket 6| or G2 and the two cars being similarly apertured, receive thereat a pivot rivet 63. In contrast, the foremost slat 48 is riveted to the horizontal flanges of the brackets Bl as at 84, while the vertical flanges of these brackets being of notably greater width, overlie and straddle snugly the sides of the braces 43 and 49 when the slat. 46 is in utility position as indicated in Figs. 3, 4 and 5. In this way, there is imparted a firmness or rigidity to the brace elements 48 and 48 by reason of the overlap flange portions 65 since the hinge brackets 5! together with their transverse slat 46 functioning in a dual capacity constitute a rigid securing strut.

Thus, there has been described the top level foldable tread platform in which there has been embodied one of the principles of th present invention productive of a condition of rigidity and susceptible of alternative positioning in order to give access to a next lower tread, which, as illustrated in Figs. 2 to 5, is generally designated 86. It, too, is comprised of a pair of angular cross section brace members 81 and 68 on one side, and 69 and H on the opposite side, see particularly Fig. 2. In all respects, this tread may be observed to resemble th first ioldable tread aforedescribed, but for the prominent difference that the swingable portion, carried by the hinge brackets 12 and 13 in this insance, is significantly wider and is comprised of two slats or tread boards 15 and i6. By referring to Figs. 12 and 13 in which the components of this step are illustrated in larger detail, it will be observed that the brackets 61 and 88 are similarly pivoted on pivotal rivets H and 18 in the stiles 29 and 44, while being mutually connected as at 19 by a common pivot rivet thereat.

As in the case of the first swingable tread member, which is characterized by the provision of the hinging arrangement at 8!, the tread portion 15-16 may be positioned as illustrated in Fig. 2 or as illustrated in Fig. 12 to suit varying needs. The pivots 18 of the rear stiles 44 and 45 extend through elongated openings 82 in the angle member brackets 88. Thus, there is described two uppermost consecutively spaced platform treads, each characterized by the provision of means for swinging a portion of the tread out of utility position in order to afford a greater overlying clearance for or accessibility to nethermost treads.

In the embodiments featured in Figs. 1, 3 and 5, a third type of tread indicated 83 is provided in which three slats designated 84 are secured onto the horizontal flanges of a pair of opposite angle brackets 85 and 86. The aforedescribed brackets have pivotal articulation at 8'! with companion brackets 88 and 88 as best indicated in Figs. 2, 4 and 5. Tread 83 differs from the other two aforedescribed treads by having no provision for being swung out of utility position since it is contemplated as the lowermost of a series of three platform treads, it being understood that whatever number happens to be chosen as such series, the lowermost one of them need not partake of the pivotal displacement of its tread component. Also, as regards the nonswingable tread 83, it is to be observed that the end pivots 9| and 92, whereby brackets 85 and 88 are engaged to the stiles 3| and 45. are both with round pivot holes in contradistinction from the elongated ones such as 82 and 55.

When the ladder is to be folded up to assume the position for storage as indicated in Fig. 15, all of the pairs of brackets or brace components 48 and 53, 61 and 68, as Well as 85 and B8 are caused to be folded about their respective pivots 52, 19 and 81 after the manner suggested by Figs. 4, and 13 and since the lengths of the lever components are different and may not be regulated to have the same angle of relative position, compensation is provided for through the elongated holes 55 and 82 which will permit longitudinal displacement of the links 53 and 68 during the folding operations as well as during erection of the platforms in utility positions whereby an approximation of parallelism is achieved.

In an eight foot ladder such as is exemplified by the illustration in Figs. 2-5 reaching the top foldable platform from the door level is not feasible for average height adults. Consequently, there have been provided means whereby the top platform may be manipulated through the medium of an extension link 96 which is pivoted as at 91, Figs. 2 and 3, to the brace element 48. The lower extremity of link 96 is provided with a manipulation nob l0l which extends low enough to be within practical reach of average height users, and at 99 this link is provided with a slot aperture within which there extends a slidable headed rivet I02, see particularly Fig. 6, which is anchored as at 103 to the vertical flange of brace element 51.

In this way, when it is intended to fold the ladder from the position shown from Fig. 3 to the intermediate position shown in Fig. 4 and eventually to achieve the fully folded condition shown in Fig. 15, the nob l0l is thrust upwardly, breaking the straight angle in the topmost tread after which by continued motion of the link 96 or by direct application of vertical force to the second platform step 65, both of these members may be made to assume the condition shown in Fig. 4 in contemplation of succeeding manipulation of the same nature to be applied against the third platform tread B3.

In order to assure that the uppermost platform treads maintain their broken toggle conditions as a result of the just described manipulations illustrated in Fig. 4, the pivotal articulations 52 and I9, between brace elements 49 and 53 on the one hand, and 91 and 68 on the other, are spaced from each other and therebetween is inserted a yieldable compression disc I03, see particularly Figs. 9 and 11. A disc of this type is preferably installed at each of the brace element pivotal junctions on both sides of the ladder. As a con sequence, a degree of spring tension, adequate to survive loosening effects which result from wear, is effected whereby the breaking of the toggle joints and the maintenance of the broken condition thereof is assured to continue throughout years of use under all practical conditions of operation. The wafer disc I93 may be a simple circular sprin disc to which is imparted a transverse curvature before hardening or if preferred, this tensioning element may be constructed after the manner of numerous well known designs of discs of this class capable of maintaining end thrust tension indefinitely.

In order that the manipulation link 96 and its companion apparatus including the rivet heads of pivotal elements 91 and I02 may not interfere with the ladder stiles during the fully folded position of the ladder as illustrated in Fig. 15, pivotal stud rivets 11 and 18 as well as their counterparts 5| and 54 on the uppermost tread are preferably made somewhat longer, note particularly Fig. 10, and are provided with spacers I94. For the same purpose pivotal studs 9i and 92 are correspondingly constructed, note Fig. '7, being provided with spacers of adequate depth or thickness. In order that the uppermost extremity of link 96 be afforded adequate clearance in respect to its adjacent pivot head 52, it is preferably provided with a spacer element 106 while the slidable step I02 is correspondingly provided with a spacer I01. During assembly, these rivets and rivet studs are headed by means of conventional operating methods so as to embrace their several contained members leaving adequate clearance only to afford pivotal or slidable movement as the case may be.

While the present invention has been explained and described in reference to specifically contemplated embodiments of disclosure, it will be understood, nevertheless, that numerous modifications and variations may be incorporated without departing from the essential spirit or scope thereof. It is accordingly not intended that the disclosure in the accompanying drawings nor the language of the foregoing description constitute any limitation upon the interpretation or scope of the invention except as indicated by the hereunto appended claims.

I claim:

1. A stepladder construction comprising, a pair of frontal stiles, a pair of bracing stiles foldable towards and away from said frontal stiles, a plurality of platform treads each at a different level and disposed adjacent said frontal stiles, said platform treads being comprised of a plurality of tread slats, a pair of angle-metal brace members at each tread level for supporting the ends of said treads as well as for spanning and structurally rigidifying the frontal and brace stiles by being pivotally connected at its ends thereto, and means for supporting certain of the slats of each tread in a pivotally displaceable manner on its related angle-metal brace members comprising formed end pieces traversing the width of said pivotal slats at the ends thereof and having projecting pivot ears integral therewith which ears are pivotally articulated to corresponding ears integrated with said angle-metal brace members.

2. The combination set forth in claim 1 including thrust links articulating pluralities of said angle brace members on each side of said ladder and extending in a vertical direction to be manipulated for breaking the straight angle alignment of the brace members in order to achieve their simultaneous folding.

3. The combination set forth in claim 2 in which said manipulating thrust links are provided with elongated slots for receiving pivot extensions of said brace members whereby to compensate for variations in movement during folding of said members from their utility positions to their folded condition.

4. The combination set forth in claim 2 in which said brace members are provided with a slot pivotal connection at an extremity and a spring tensioning element at an intermediate pivot junction whereby the breaking or re-establishing of a straight angle condition of each bracket may be performed independently of the condition of the other members of the ladder which are mutually joined by said manipulation link.

5. A folding stepladder comprised of a top level platform head having depending metallic flange sides secured thereto, a pair of tread rails secured at their upper ends to said flanges, a pair of brace rails pivoted at their upper ends to said side flanges to be movable towards and away from said tread rails, a pair of lower level span brackets connecting said tread and brace rails each bracket comprising link components of right angular cross sections pivoted at extreme ends to said tread and brace rails and at adjacent ends to each other, one of said link components having a cantilever overhang to limit the pivotal motion in one direction to a straight angle alignment between said bracket components, a plurality of pairs of high level span brackets similarly comprised and pivoted to said tread and brace rails at their extremities and correspondingly pivoted to each other, one of said higher level bracket components of each pair having an elongated articulation hole at its pivot with its related rail, foldable treads carried by said higher level brackets and means for urging said higher level brackets parallelly into folding pivotal movement.

6. In a folding stand-up type stepladder, opposed front and rear ladder rail members, a plurality of foldable struts connecting said front and rear members at different horizontal levels, said foldable struts comprising substantially symmetrical components mutually pivoted to each other at adjacency, and pivot tensioning 40 means comprising spring pressure discs carried at the mutual pivots between each pair of strut components whereby each strut may be positioned or moved and accordingly thereat frictionally maintained independent of marginal positioning or movement of other of said struts.

'7. A stepladder construction comprising tread rails and brace rails foldable toward and away from each other, a plurality of treads at spaced elevations along said tread rails each tread being pivotally articulated at its ends whereby it may be rotatably displaced between utility and receded positions, brace link assemblies connecting said tread and brace rails at corresponding spaced elevations and affording journal support to the end pivots of said treads, said assemblies being foldable at intermediate pivotal junctions and constructed of angle metal and one link overlying the other, and transverse rigid connectors for folding all of said brace links in unison during the folding together of said brace rails and said tread rails.

CECIL F. HANSEN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 650,006 Haas May 22, 1900 861,583 Foster July 30, 1907 950,469 Barth Mar. 1, 1910 1,820,330 Sittig Aug. 25, 1931 1,930,004 Schramm Nov. 6, 1934 2,146,020 Lewis Feb. 7, 1939 2,368,622 Tarvin Feb. 6, 1945 2,479,736 Fieroh Aug. 23, 1949 FOREIGN PATENTS Number Country Date 88,730 Germany Oct. 3, 1896 4,412 Great Britain Feb. 27, 1908

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