US2896830A - Combined step and stairway and extension ladder - Google Patents

Description

Ja -A July 28, 1959 R. I. BAlR I 2,896,830 comsmmn STEP mm STA IRWAY AND ErxwsusIon LAovsa Filed May 21. 1957 I I 4 Sheets-Sheet 1 I INVENTOR. ROGER I. BAIR July 28, 1959 l, I 2,896,830

COMBINED STEP AND STAIRWAY AND EXTENSION LADDER Filed May 21, 1957. I 4 Sheets-Sheet 2 INVENTOR.

ROGER BA/R y 1959' .R. l. BAIR 2,896,830

COMBINED STEP AND STAIRWAY AND EXTENSION' LADDER Filed May 21, 1957 4 Sheets-Sheet a INVENTOR. ROGER I. BA IR July 28, 1959 1 R. LBA IR 2,396,830

I COMBINED STEP AND STAIRWAY AND EXTENSION LADDER Filed May 21, 1957 4 Sheets-Sheet 4 I INVENTOR. ROGER I. BAI R COMBINED STEP 'AND STAIRWAY AND. EXTENSION LADDER Roger I. Bair, Baltimore, Md.

Application May 21, 1957, Serial'No. 660,585

Claims, (Cl; 228-25) of these uses it shall'berigid, secure, and be safe to use.

A further object is to provide for conveniently entirely separating the two ladder sections, permitting the sections to be used as two ladders, each in a manner which I may term a wallladder, shelf ladder, or garden ladder, and the two sections may be separately propped against adjacent walls and support a board, and thus provide a sturdy scaffold.

The composite ladder is light weight, easy to'handle, and convenient to be arranged in any of its positions for its various uses without the use. of special tools.

A further general object is to so construct the ladder that it may be cheaply'manufactured and may be constructed either of wood or metal.

A more specificobject is to so. construct the interconnecting means that the prop section may be readily slid longitudinally without disconnection, and when in the desired position, the sections may be firmly interlocked in any of the extended positions.

A still further specific object is to provide a novel form of spreader,.preferably pivoted. to the step section, and having a resilient means for embracing a rung on the prop sectionnot only firmly establishing the acute angle relationship, but which shall avoid inadvertent disconnection or loosening.

The present invention constitutes a modification of and improvement upon the combined stepladder construction disclosed and claimed in Reissue Patent No. 24,282, dated February 26, 1957, granted to Harry P. Bair.

Other objects and advantages will become apparent in the following descriptionv which relates to the accompanying drawings, in which:

Fig. l is a side elevation of this improved combination ladder showing it in position for'use as step'ladder;

Fig. 2 is a side View of the ladder showing it in position for use as an extension ladder;

Fig. 3 is a side View ofthe ladder showing itpositioned for use on a stairway;

Fig. 4 is a fragmentary side elevation on an enlarged scale showing the connection at the upper'portions of the step, and prop .sections and. illustrating the bracing spreader in position;

Fig. 5 is a fragmentary top plan'on a further enlarged scale illustrating one end of the top step and. the upper portions of the adjacent side rails of the two; sections, andfa portion of the spreader brace;

2,896,830 Patented July 28, 1959 Fig. 6 is a fragmentary vertical section through the top step of the step section and through a rung of the prop section, and' showing the connecting members when in the position foruse on a stairway;

Fig. 7 is a sectionalview looking upwardly under the top step, taken ona plane indicated by'the line 7-'-7 of Fig. 6;

Fig. 8 is a side elevation of the upper portions of the step and prop sections in stepladder position andshowing a construction wherein the step and prop sections are made of metal instead ofwood; and

Fig. 9 is a view similar to Fig. 5 being a fragmentary plan of the step and prop sections in the position shown in Fig. 8.

The constructions shown in the drawings illustrate preferred embodiments adapted for both wood and metal ladders, and these constructions will now be described with the use of characters of reference.

The step section or stepladder portion of the embodiment in wood, shown in Figs. 1 to 7, comprises side rails 1 and steps 2, the stepsbeing rabbeted into the side rails at their ends, and they are preferably reinforced by the cross tie rods beneath, the steps, the ends of which are shown at 3. The top'step 5 rests upon and extends overthe ends of the side. rails andis so supported and shaped as to coact with related parts.

The prop section comprises similar side rails 6 secured to the ends of rungs7 forming the steps whenused as an extension ladder. or separately. As indicated in the stated objects, the two sections of the ladder may take any of the several positions. mentioned, and, for convenience, the connecting and sup orting means functioning to hold thesesections will bedescribed in reference first to their position. as a stepladd'er resting upon a flat surface or floor, .as. shown in Fig. l, and more in detail in Figs. 4 and 5.

At the upper ends. of each side rail 1 is a bracket member comprising a.'sheet metal element having a .fiat

portion 10 through,which' extend a plurality of rivets.

or bolts, as indicated at 12; 'I hisme'mber has an outwardly extending flange. 14 fitting under the overhanging ends 15 of the top step 5. These brackets are formed in left and right forms. so that one may be fitted to. the side rail at oneend of thetop step, while the other may cor.-

respondingly be secured to the opposite side rail top step. This flange may be secured by rivets or bolts.

16 to the overhanging endof the step, as shown particularly in Figs. 5, 6, and 7.

The plate member 10 extends parallel with the outer side of the rail 1 for a distance suflicient to bridge over the side of the rail 6 of the prop section where it is fitted with a guiding hooked end portionextending across the outer edge of the rail 6 at 18 and inwardly again at 19. The major part ofthe cross portion 18 slopes to bring. it into parallelism with the normal angle of the rail 1, and the lower edgeis provided with a bracing lip at a different angle, as indicated at 20, which may engage the'outer edge of the rail 6. This point of engagement may have a reinforcing strip on each side rail as indicatedat 21. The upper edge of the plate 10 is formed in a compound curve, a portion of which provides a hook-shaped notch 25 engaging an outwardly extended metal pin 26 which preferably is coaxial with and fitted into thetopmost rung 7 of the prop section.

A notch is formed in the end of the top step whereby the-overhanging end His-narrowed as at 30. The wider' portion of the step, normallywithin therails 6', is reinflange 42 fitted under the step. The two portions 40 and 42 are unitary or integral with an outwardly extending strap portion 44 bent upwardly around and over the top of the step as at 45. The bolts 12 securing the plate preferably also extend through the plate 40 of this bracket, while additional rivets or bolts 46 may extend htrough the step and flange 42.

When the ladder is in the position shown in Fig. 1, the parts will be fitted together as they more clearly appear in Figs. 4 and 5. Here it will be seen that the pins 26 fit the inner part of the hooked notch 25, and the hook portion tends normally to rest firmly against the outer side of the side rail at its reinforcing strip 21. Obviously, however, this spacing and resulting leverage may subject the connecting parts to severe strain in the absence o'f'additional connection further down on the ladder. Accordingly, at a suitable distance from the apex on the angle formed by the two sections, it is desirable to provide additional bracing means, normally referred to as a spreader, which, in the present instance, is of novel construction.

A bail-shaped strip having parallel side portions 50, suitably pivoted as at 52 to the side rails 1, extend inside of the side rails 1 and 6 and transversely as at 53, whereby this bail may be swung from the position shown in solid lines to that shown in dot and dash lines between the rails 1 where it clears the rung 7 when the prop section is being positioned for and used as an extension ladder.

Extending preferably several inches along the mid-section of the bridge 53 of the bail and rigidly secured thereto is a spring clip hook 55 of thin metal shaped to extend slightly more than half-way around a rung 7, and having its outer lip portion curled as at 56 for conveniently spreading the clip with the fingers to release it. When so released, it may be swung upwardly and spring beneath a knob or projection 57 on the under side of the top step, and thus be held in its inactive position permitting free movement and positioning of the prop section.

Obviously, this spreader bail and hook may securely brace the two sections in their desired acute angle position, and, incidentally, this bracing makes it convenient to pick up the ladder in its spread position for moving it about when in use as a stepladder, inasmuch as the sections of the ladder are thus held in rigid relationship.

When the two sections are positioned for use as an extension ladder, as shown in Fig. 2, the functioning, while somewhat similar to that of the Bair reissue patent, No. 24,282, above mentioned, differs in that the rungs of the prop section may be seated in rigid hooks 60. These hooks are formed of strip metal and have shank portions 61 fitted into recesses in the first step from the top, and there secured as by screws 62 to this step. Obviously, any of the rungs, except the top rung of the prop section, may firmly seat at these hooks 60, thus supporting the section in the various extension ladder positions. To change from the stepladder position to the extension position, it is only necessary to release the spreader hook 55 and swing its bail upwardly, as shown in the broken lines in Fig. 4; then swing the prop section inwardly freeing the pins 26 from the hook notch bring the prop section into parallelism at the desired height, and then drop the selected rung into the hooks 60-.

An important modification of the present ladder from that of the identified reissue patent is the arrangement for providing the vertical stop for the prop section when the ladder is used on different levels, as on a stairway. Here again, the spreader hook 55 is detached from its rung and the pins 26 from the hooked notches 25, the two sections then placed on the supporting surfaces, as shown in Fig. 3, with the prop section on a stair step S, for example, and the extended inner or back edge of the top step 1 will thus project into the path of the adjacent prop section rung 7. This rung may contact the reinforcing strips 44, as appears particularly in Figs. 6 and 7. Now, the outer edges of the prop section rails 6 will engageth'e short bevels 20 of the hooks 18, limiting the spreading angle, which, however, is further exactly determined and held between the two sections by re-engaging the spreader hook 55 with the rung 7 next below the rung engaging the top step 5. It will be seen that the prop section may be positioned at various relative heights to the step section, and that the user may conveniently stand on any or all of the steps of the step section, or, if desired, may stand on and grasp rungs of the prop section with safety.

To avoid any slippage of the ladder sections in any of these positions, the bottom ends of the rails 1 and 6 may be fitted with non-skid rubber safety shoes 70 and 71, respectively, generally arcuate and are notched or serrated, as shown.

Obviously, the two sections may be used independently. If the two sections are each propped against a wall in a position suitable to be bridged by a board or plank, the sections may form with such plank a very satisfactory and readily usable scafiold.

A corresponding arrangement of parts, functioning in the manner above described for positioning and holding the sections in the several relative positions, may be embodied in a metal construction, as illustrated in Figs. 8 and 9. Here, the step section 81 and prop section 86 are formed of channels. The steps 82 have downturned flanges as at 83, and the step and flanges extend between -inturned side flanges 84 and are suitably secured as by rivets connecting the step and side rail flanges.

The top step 85 is formed of metal and is secured'to the upper ends of the step section channels. These steps are arranged to stand horizontally when the section is in its normal sloping position, and each may be provided with non-skid ribs.

The prop section side rails 86 are formed of channel members also having inturned flanges. These side rails are connected by rungs 87 which are preferably metal tubes secured to the webs of the channels in any suitable fashion, as by an enlarged bead at the inner side of each channel web, while the tube extends through an opening in the web and has its outer end spun outwardly, as indicated at 88.

The upper rung 87 may be provided with a plug or other means for securing the outwardly projecting pin 26 engaging the hooked notch 25 formed in the plate 10a, corresponding to the plate 10 of the wooden ladder con struction described. This plate is shaped at 18 and 20 and with the inturned hook portion 19 as before, and may be riveted to the web of the adjacent side rail. A flange similar to that of the flange 42 may extend outwardly beneath an overhanging portion of the top step 85 and be riveted or bolted as at 91, as appears particularly in Fig. 9.

The top step 85 may have an inwardly extending lip ofiset at its ends to clear the side rails 86 of the prop section. This overhanging portion is indicated at 90 and projects far enough to engage the selected rung 87 in the same manner as the extension and brace straps 44 engage the rung 7 in Fig. 6, for stair step position. The upper end of the inner flange of the side railsof the step section is turned forwardly forming a beveled portion 93 corresponding to the angle of the position of the prop section and against which the inner flange of the prop section may rest at its upper end when in stepladder position, as

shown in Fig. 8, and which may also engage the side rail flange in the stair step position. a

.The upper ends of the propsection may be closed by a rounded cap piece indicated at 89. This part may be a casting or stamping fitted between the flanges and extending downwardly for a distance, while an overhanging portion fits a rounded extension of the web of the side rail.

The spreader brace 50 and its' hook 55 maybe constructed substantially'in the manner described, except that at the pivoted ends of the bail strap it is offset and is pivoted as at 52a to the web of, the step section side rails.

The hooks 60 may have their extensions 61 lie on the top of a metal step 82 and be riveted thereto.

Obviously, when the pin 25 is disengaged from its hook slot 25, and the spreader brace is disconnected and moved to inoperative position, as before, the prop section may be extended in parallel position for the extension ladder, or may be moved upwardly bringing one of the lower rungs against the under side of the inwardly extending flange 90 for the different stair step positions. In the latter case, the spreader brace would again be repositioned, engaging the next rung below.

From the foregoing description it will be seen that whether constructed essentially of wood or entirely of metal, the present invention provides a multiple purpose ladder of great simplicity, convenience in use, and safety in any of its usable positions.

Having thus described my invention, what I claim is:

1. In a combination stepladder of the type comprising a step section and a prop section, each section having spaced flat parallel side rails with parallel inner and outer edges and steps and rungs, respectively, carried by the side rails, spaced parallel brackets rigid with the step section adjacent the upper end thereof and extending over the outer sides of the rails of the prop section and having hook-shaped portions extending around the outer edges of and slidably embracing the side rails of the prop section permitting longitudinal movement of the prop section relative to the step section, pins projecting outwardly from the side rails of the prop section, said brackets having hook-shaped recesses formed in their upper sides and pivotally engaging said pins and serving to prevent relative movement upwardly or downwardly between the two sections and permitting the pins to be disengaged for vertical sliding of the prop section relative to the step section, a hook rigid with the step section positioned to engage a selected rung of the prop section when slid upwardly in parallel position to support it as an extension ladder, a bracing spreader pivoted to the step section and having a spring hook to engage a substantial portion of the length of a rung of the prop section when it is at an angle to the step section, and a top step on the step section having a rigid transversely extending projecting portion adapted to engage a rung of the prop section when the prop section is at an angle thereto and in a relative elevated position and while the side rails thereof are embraced by said hook-shaped portions of said brackets at their outer edges to hold the rung beneath and in engagement with said top step projecting portion.

2. The structure defined in claim 1 which includes a reinforcing metal bracket having flange portions fitting the underside of the top step and having another flange secured to the side rail, and having a reinforcing extension embracing the edge of the widened transversely extended part of the top step and positioned to contact a rung of the prop section. i

3. A ladder comprising a step section and a prop section adapted to be used as a stepladder resting on a flat surface, and as an extension ladder with the sections approximately parallel, and as a stairway ladder with said sections at an angle with the prop section elevated with re lation to the step section, the two sections comprising side rails connected by steps and rungs, respectively, the step section having rigid bracket members at the top thereof extending around and slidably embracing the rails of the prop section, each of said brackets including notches forming overhanging hooked portions at their upper sides, pins extending outwardly near the upper ends of the prop section side rails and adapted to fit into said hook recesses to anchor the sections at relatively fixed vertical positions when at an angle to each other for stepladder position and adapted to be detached when the sections are brought into approximate parallelism for. relative vertical adjustment as an extension ladder, said step section having a top step rigid therewith and provided with a rigid extension projection rearwardly a distance such as to clear the rungs of the prop section when being moved in substantial parallelism and while extending sufiiciently to engage a selected rung below the top of the prop section and prevent relative upward movement thereof when the prop section is positioned on a surface at a higher level than that on which the step section rests, and when the prop section is at an angle to the step section, and while the bracket members serve to hold the rails of the prop section in position with the selected rung in engagement with said rigid extension of the top step.

4. The stepladder structure defined in claim 3 in which each end of the top step portion of the step section is provided with a beveled surface normally parallel to and adapted to be engaged by the inner edge of the prop section side rail when it is at an acute angle and is raised for stairway engaging position.

5. In a combination stepladder of the type comprising a step section and a prop section, each section having spaced side rails and steps and rungs respectively carried by the side rails, spaced parallel brackets rigid with the step section adjacent the upper end thereof and extending over the outer sides of the rails of the prop section and having hook-shaped portions extending around and slidably embracing the side rails of the prop section permitting longitudinal movement of the prop section [1'61- ative to the step section, a rigid rung-engaging element positioned at the top step of the step section and extending between the side rails of the prop section a distance sufiicient to engage a rung of the prop section when the sections are relatively spread at an included acute angle, and said hook portions of the brackets engaging the opposite edges of the side rails of the prop section being spaced from the side rails of the step section sufiicient to allow the rungs to pass said projection when the prop section is being moved upwardly or downwardly in a sub stantially parallel relation to the step section, the hookshaped portions engaging the side rails of the prop section being so spaced from the side rails of the step section and from said rigid rung-engaging element at the top step of the step section that a rung engaged by said element of the top step is maintained in engaging position when the ladder sections are spread at an acute angle and while the prop section is raised for a stairway position.

References Cited in the file of this patent UNITED STATES PATENTS 214,377 Dyer Apr. 15, 1879 771,352 'Clough Oct. 4, 1904 1,050,273 Handy Jan. 14, 1913 1,283,212 Kloepfer Oct. 29, 1918 1,984,655 Rassmussen Dec. 18, 1934 1,996,133 White Apr. 2, 1935 2,675,155 Bair Apr. 13, 1954 FOREIGN PATENTS 5,905 Australia Feb. 9, 1927 447,498 Italy Apr. 12, 1949

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