US2510515A

US2510515A - Ladder

Info

Publication number: US2510515A
Application number: US604866A
Authority: US
Inventors: Curt E Nyberg; Raymond T Larson
Original assignee: IMAGINEERING CORP
Current assignee: IMAGINEERING Corp
Priority date: 1945-07-13
Filing date: 1945-07-13
Publication date: 1950-06-06
Anticipated expiration: 1967-06-06

Description

June 6, 1950 c. E. NYBERG ETAL LADDER 2 Sheets-Sheet 1 Filed July 13, 1945 June 6, 1950 c, E, NYBEG Em 2,510,515

LADDER I Filed July 13, 1945 2 Sheets-Sheet 2 [Xi d6?! wf 5, @Z@ 25 Patented June 6, 1950 UNITED STATES PATENT OFFICE LADDER Application July 13., 1945, Serial No. 6%,866

Claims. (Cl. 228'-56) This invention relates to ladders, and more particularly to stepladders formed of sheet metal or similar material.

An object of the invention is to provide a ladder which may be constructed in a novel manner with integral connecting means and with means providing a roughened surface for the steps of the ladder. A further object is to provide a ladder having improved means for supporting steps firmly upon the frame structure and in ready assembly and knocked-down relation thereto. A further object is to provide an improved ladder structure equipped with extensible pail-holding means and spreader bar support. Yet another object is to provide a ladder of improved construction which may be assembled in a minimum of time to provide an extremely sturdy structure and which provides means for locking the back sup-.- port and ladder frame rigidly together during use. Other specific objects and advantages will appear as" the specification proceeds.

The invention is illustrated in a preferred embodiment, by the accompanying drawings, in which- Figure l is a perspective view of a ladder embodying my invention; Fig. 2, a front view in elevation; Fig. 3, a transverse sectional view of a step structure, the section being taken as indicated at line 3 of Fig. 2; Fig. 4, a transverse sectional View of a side rail of the frame, the section being taken as indicated at line 4 of Fig. 2; Fig. 5, a perspective exploded View of the connecting structure between a side rail and step; Fig. 6, a detail sectional view, the section being taken as indicated at line 6 of Fig. 2; Fig. 7, a sectional view of the top step or platform of the ladder showing the pail-supporting means; Fig. 8, a transverse sectional view, the section being taken as indicated at line 8 of Fig. '7; Fig. 9, a view similar to Fig. '7 but showing the pail support equipped with a handle; and Fig. .0, a broken perspective view of the top backportion of the ladder showing a modified form of pail-supporting means.

In the illustrationgiven, A designates a ladder frame; and B, a back support therefor.

The ladder frame A may be constructed of any suitable material. We prefer to employ sheet metal. In the illustration, each of the side rails mis constructed as best shown in Fig. 4, the metal being rolled at the edges to form tubular members H and the inner portions of the metal at l2 brought flat against the central web of the material. The central web ispreferably provided with eyelets l3 and a portion of each strip [2 is 2 turned inwardly through the opening l3 to form a locking connection l4.

Each of the side rails is also provided with a step-supporting bracket 15 which may, if desired, be struck from the central web of the member ll itself to form an integral bracket. In the struc-- ture shown, a separate bracket member I5 is formed, and this is provided with a back wall i6 which. may be spot-welded or otherwise secured to the central web'of the member I0 at a point between the openings; l1. Each bracket [5 is equipped with a top fiat wall I8 and with a socket portion IS on each side of the wall I8, as shown more clearly in Figs. 5 and 6.

The steps 20 are also preferably constructed of sheet metal and in the form illustrated in Fig. 3, although the construction may be varied considerably in detail. In the construction shown, the ends of the step are provided with tubular portions 2|, and the inner horizontal portions 22 have upwardly-struck integral portions 23 extending through openings 24 in the central web of the structure 20; In forming the openings 24' in the web portion of the step, we prefer to turn back the metal of the web to form a rim or rolled-back edge '25. The forming of the opening by peeling back the metal provides an. eyelet structure, and the clenching of the integral fingers 23 from the strip 22 about the rolled edge 25 provides not only a sturdy interlock but a plurality of raised members having out edge portions adapted to serve effectively for gripping the soles of the shoes to prevent slipping upon the ladder step. The ladder is preferably provided with superficial roughening or knurling along the edges of the step, and these cooperate with the eyelet structure described to prevent. slipping upon the surface of the metal web.

The eyelet structure described shows at least four leaves or projections of the member 23 which thus afford angularly-related means extending in different. directions for preventing slipping in any position. If desired, the struc ture may be modified so as to provide at least one projecting member 23 and preferably two or three or any increased. number of elements" in in angular relation.

The step as may also be provided with a series of openings 21 which may be located in the central web and which serve also to prevent slipping upon the metal surface or the web as well as lightening the weight of the structure;

7 The top of the rails is preferably secured by a topstep or platform 28 formed of sheet metal and having side portions or depending flanges 29 extending downwardly along the rails ill.

The back support B preferably comprises an upright 30 which may be constructed similarly to one of the side rails Ill having rolled edge portions 3|. The bottom end of the upright is secured within a yoke member 32 having depending spaced-apart foot rests 33. The top of the upright 30 is also preferably received within a yoke member 34 having upwardly-extending and widely-spaced arms 35 secured by a pivot rod to the side rails H].

A spreader bar member C is provided as best illustrated in Figs. 1 and 6. The rear arm 36 of the bar is pivotally connected to a bracket 31 carried by the back support B. The forward end of arm 36 is pivotally connected to a bifurcated member 38 which has arms 39 extending over a step 20 and are pivotally secured to the rails H3 near the forward edges of the rails I0. With this construction, the step 2!] supports the arms 3& against downward movement and prevents any tendency of the spreader bar to collapse during use as a result of any pressure exerted upon the bar.

We prefer to equip the ladder with an extensible member adapted to serve as a pail holder. In the structure shown in Figs. 7 and 8, an angle bar member 40, provided at its ends with notches 4! adapted to receive a pail, is slidable mounted within slots 42 provided in the depending flanges 29 of the top step or platform 28. The platform 28 is provided with a longitudinal slot 43 through which the neck 44 of a rivet extends, the head 45 of the rivet engaging the top surface of the platform 28 and serving to slidably support the rail or angle bar 4!) in position. If desired, the bar 45! may be provided with a depending handle 46 for facilitating shifting of the bar laterally, as shown more clearly in Fig. 9. In the structure shown in Fig. 9, the platform 28 is not slotted and the rail 51 is supported normally by the depending slotted flange 29.

A modified type of pail holder is shown in Fig. 10 in which a single bar 48 is pivotally supported at 49 upon the yoke 34. On each side of the pivot 39 are outwardly-struck hook segments 58] which serve to support the bar when it is swung to one side or to the other. If desired, the pivot connection 49 may be made sufficiently loose so that the bar 48 may be swung outwardly to clear the hooks 59 and thus lie normally fiat upon the upright 30 so as to avoid projecting from the structure during shipment.

In the operation of the apparatus, the parts may be shipped in knocked-down relation and readily assembled at the point where the ladder is to be sold or used. For assembly of the steps 20 upon the brackets l carried by the side rails II], it is only necessary to press the steps into the spring sockets I9 of the brackets 15. The tubular portions 2| of the step spring snugly into the sockets l9 and tend to lock the step firmly in position thereon. If desired, any suitable means for permanently locking the step upon the bracket may be employed. However, for normal purposes, the spring grip of the tubular members 2| about the bracket wall [8 and sockets l9 serves to lock the steps securely in position. For disassembly, he steps may be simply pressed out of the interlocking connection with brackets E5.

The steps 20, which being formed of sheet metal ordinarily present a dangerously smooth surface, are effectively equipped against slipping by the eyelet structure shown, in which angularly-related fastening elements 23 present raw or cut edges which are most effective against slipping, and these elements are buttressed by the openings 21.

The spreader bar readily folds in an upward direction to permit the back B to swing inwardly against the rails when the ladder is to be carried from one point to another. When the ladder is spread for use, the bar C may be swung to the position shown in Figs. 1 and 6, and here further downward collapsing is automatically limited by the step 20 directly under the arms 39.

The pail-supporting rails described in Figs. 7 to 10 inclusive normally lie within the confines of the structure so as to present no obstruction or protruding sections. When it is desired to use them, however, they may be readily drawn onto either side of the ladder for supporting a pail. In the structure shown in Figs. 7 and 8, a relatively short rail 40 is employed, and. this is constantly supported in line with the slots 42 by the rivet heads 45. In the structure shown in Fig. 9, the rail 41 is considerably longer and no need for rivet heads is necessary. A handle 46 enables the bar to be moved with facility from one side to the other. In the structure shown in- Fig. 10, the bar 48 is provided with end notches in both sides thereof so that the bar may be swung from one side to the other and on either side present pail-supporting notches. The loops 59 are eiiective for supporting the bar on either side of its pivotal movement.

While in the foregoing specification we have set forth certain details of structure as illustrating one mode of the invention, it will be understood that such details may be widely varied by those skilled in the art without departing from the spirit of our invention.

We claim:

1. A ladder comprising a pair of side rails, a back support pivotally secured to said side rails, a plurality of step-supporting brackets carried in spaced relation by the inner sides of said rails, said brackets having spaced longitudinal socket grooves therein, and a plurality of metal steps having a central web portion and having their longitudinal edge portions in the form of tubes, said tubes being received within said socket grooves of said brackets.

2. A ladder comprising a pair of side rails, a back support pivotally secured to said side rails, a plurality of step-supporting brackets carried in spaced relation by the inner sides of said rails, said brackets having spaced longitudinal socket grooves therein, and a plurality of metal steps having a central web portion and having their longitudinal edge portions in the form of tubes, said tubes being received within said socket grooves of said brackets, said tube portions being formed of spring metal and being frictionally held within said socket grooves of the brackets.

3. A ladder comprising a pair of side rails, a back support pivotally secured to said side rails, a plurality of step-supporting brackets carried in spaced relation by said rails, each of said brackets having a central plateau portion and longitudinal socket grooves flanking said plateau, and a plurality of metal steps having their longitudinal edge portions turned upon themselves to form tubes and with a central web portion connecting said tubes, said tubes being received within the socket grooves of said brackets and said web portion of each step resting upon the plateau portion of each bracket.

4. A ladder comprising a pair of side rails, each of said side rails comprising a longitudinal metal strip having its longitudinal edges rolled to form tubular supports and said tubular supports being connected by a metal Web, a plurality of step-supporting brackets secured to the metal web between the tubular supports of each rail, said brackets having spaced longitudinal socket grooves therein, and a plurality of metal steps having longitudinal edge portions turned to form tubes and said tubes resting in the socket grooves of said brackets.

5. A ladder comprising a pair of side rails each having a central web portion and edge portions rolled to form tubular supports, spaced brackets secured to the inner web portion of said rails to provide step supports, each of said brackets having spaced longitudinal socket grooves therein, and a plurality of steps having central web portions and longitudinal edge portions rolled to form spaced tubes adapted to be received in frictional gripping relation within said socket grooves of the brackets.

CURT E. NYBERG. RAYMOND T. LARSON.

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

UNITED STATES PATENTS Number Name Date 448,648 Gardner Mar. 24, 1891 475,164 Sprague May '17, 1892 775,498 Parsons et a1. Nov. 22, 1904 777,069 Boyer Dec. 13, 1904 870,334 Adler Nov. 5, 1907 1,045,957 Dicks Dec. 3, 1912 1,101,359 Thompson June 23, 1914 1,109 228 Houston Sept. 1, 1914 1,478,277 Hall Dec. 18, 1923 1,753,060 Myerstuen Apr. 1, 1930 1,972,064 Moushon Aug. 28, 1934 1,996 515 Howell Apr. 2, 1935 2,049,925 Rafter Aug. 4, 1936 2,162,022 Mansfield June 13, 1939 2,208,866 Hannaford July 23, 1940 2,265,735 Lambert Dec. 9, 1941 2,390,000 Sampson Nov. 27, 1945