US1555483A - Ladder - Google Patents

Description

Sept. 29, 1925. 1,555,483

H. ROSENBERG LADDER Filed Deo. 12', 1923 2 Sheets-Sheet 1 Sept. 29, 1925. 1,555,483 H. ROSENBERGy LADDER Filed Deo. 12, 1923 2 Sheets-Sheet 2 Ww zu a www M l fm m M Patented Sept. 29, 1925.

UNITED STATES HEYMAN ROSENBEBG, 0F NEW YORK, N. Y.

LADDER.

Application led December 12, 1923. Serial No. 880,195.

To all whom t may cofrwem.' v

Be it known that-I, HEYMAN RosENnERo, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Ladders; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in ladders of the type usually em loyed for household purposes, and common y referred to as step ladders.

The r1rnary object in view is the production ofpsuch a ladder which is characterized by its lightness, durability, efficient operation, sanitation and inexpensiveness of construction.

With this and further objects in view as will in part hereinafter become apparent and in part be stated, the invention comprises certain novel constructions, combinations and arrangements of parts as subsequently specified and claimed.

In the accompanying drawings,

Figure 1 is a view in side elevation of a ladder embodyin the features of the present invention, e parts being shown; in dotted lines in their folded position.

Figure 2 is a front elevation thereof.

Figure 3 is an enlarged, detail, fragmentary section taken on the plane indicated by line 3 3 of Figure 2.

Figure 4 .is a horizontal section taken on the plane indicated by line 4 4 of Figure 3.

Figure 5 is an enlarged plan view of a fragment of the platform.. y

Figure 6 is a vertical sect1on taken on the Iplane indicated by line 6 6 of Figure 5.

Figure 7 is an enlarged plan view of a fragment of one of the treads.

Figure 8 is a vertical section therethrough taken on the plane indicated by line. 8 8 of Figure 7.

Figure 9 is a fragmentary, vertical section taken on the plane indicated by line 9 9 of Figure 1.

Referring to the drawings by numerals, 1 indicates the side bars connected by the treads 2 and pivotally engaging the platform or table 3, which latter 1s in turn 1votally connected with the legs 4. The egs 4 are connected near their lower extremities by the cross bar 5, which is preferably stiffened and strengthened by corner fillets or brackets 6, 6, fixed t0 the bar 5, and to the respective legs 4. The legs 4 and the side bars 1 are preferably formed channelshaped in cross section, being comprised preferablyr of relatively light gauge commercial c annel irons. The bar 5 is preferably of angle iron and, as indicated in Figure 1, is riveted or otherwise appropriately fixed to the outer flange of the respective channel irons 4 with the corner plates 6 interposed between such flange and bar 5. The channel irons 4 are also preferably connected by a tie strap 7 riveted or otherwise appropriately fixed to the outer flanges of the channels 4, and disposed at an appropriate point in the length of the channel irons 4 intermediate their upper ends and the bar 5.

Each channel iron 1 and 4 at its lower end is provided with a cushioning device 8, preferably of rubber or the like, appropriately anchored within the channel for enabling noiseless movement and positioning of the ladder. There may be as many treads 2 as desirable, according to the length of the ladder, and each consists of a plate having a depending flange extending around all of its edges, which flanges, at the ends, are riveted or otherwise appropriately anchored to the web of the respective channel irons or side bars 1. In order to enable the plate forming each of the treads 2 to be of greater width than the width of the respective side bar 1, each of said plates is formed with an extension 9 at each end, reduced so as to be of a width equal approximately to the width of the space between the flanges of the respective side bar or channel iron 1, and the pendent flange of the tread plate is set at that angle with respect to the upper surface of the plate corresponding to the angle of the side bars 1 from the vertical when in an operative position, so that the tread surface of each tread 2 is disposed horizontally when the ladder is in operative position, and at the same time the marginal flange at the places of the extensions 9 fits snugly against the flanges and web of the respective side bar or channel 1. The excess width of each tread plate beyond the width of the respective reduced extension 9 projects outward, and thus affords a substantial footing. To insure avoidance of possible slipping on any of the treads 2, incident to the fact that they are formed of metal, each tread plate 1s provided with a plurality o f upstandlng projections or cu -like formations indicated at 10, 10. The clrcular edges presented by the rojections 10 to the foot of the user of tlie ladder insures a substantial grlpping action, and, where the sole leather is sufficiently pliable, the leather .partly enters the cups 10. A part of the air being thus exhausted from those cups, the cups w1ll cause resistance to removal of the foot to an extent sufficient to assist in preventing slipping. Therefore, the miniature cups 10 may properly be referred to as vacuum cups. For purposes of finish and also to aid 1n preventing slipping, la marglnal bead .or ridge 11 is preferably formed about the tread surface of each tread 2. The bead 11 and the cups 10 are preferably formed by shaping the material of which the tread 2 is made, as, for example, by stamping the same in the instance of the tread material being of sufficient light gauge and character of sheet metal.

The table or platform 3 at the top of the ladder preferably consists of a sheet of metal formed with non-slipping or vacuum cups 12, and a marginal ridge or bead 13, corresponding respectively to the cups 10 and bead 11 of the treads. A marginal flange 14 depends from and is continuous of the edge of the platform 3. The platform 3 is, as has been stated, hinged to both the side bars 1 and the\legs 4, the hinge connection consisting of a pair of hinges, one at each side of the step ladder, that is, one at each end of the platform 3. Each of said hinges consists of av leaf or plate 15 pivoted at 16 to a plate 17. Each plate 15 consists of an angle bar with a relatively narrow horizontal web arranged at the upper edge of a relatively wide vertical web. The horizontal web of leaf 15, in each instance, is riveted or otherwise appropriately anchored, as at 28, 28, to the respective end of platform 3, while the vertical web of leaf 15 is pivoted at 19 to the web of the respective leg 4. The plate 17 consists of a similar angle plate to plate 15, though preferably slightly smaller, arranged with the horizontal web extendin inward from the upper edge of the vertical web, with the latter riveted 0r otherwise appropriately anchored to the web of the upper end portion of the respectiveV side bar 1. The hinge leaves 15 and 17 are arranged outside of the respective legs and side bars, and, in each instance, the leaf 15 is arranged in line with leaf 17, the leaf 17 being offset laterally inward for the length of the overlap of the leaf 15, as seen best in Figure 4. To facilitate formation of such offset, the horizontal web of leaf 17 is preferably cut away for the length of the offset. The horizontal webs of the leaves 17, as bestseen in Figure 4, cover the up er end of the respective side bar 1 and, w en the parts are in their unfolded position, are engaged by the under surface of the platform or table 3, which, being the equivalent of a solid extension of leaves 15 serves as an effective stop for preventing further openin of the ladder. All of the parts are thus rmly held in position when in the o en condition.

The egs 4 are connected with the side bars 1 by a brace adapted to lock the parts against collapse when they are in their open or extended position, as seen in full lines in Fi re l, and the said brace consists of a pair of rods 18, 18 arranged to cross each other and pivoted together at 18', at the point of crossing, each rod 18 having its ends pivoted at 20 to one of the legs 4, and at 21 to one of the side bars 1. Each of the pivotal connections 20 and 21 is identical in structure, as seen in Figure 9, and consists of a projection 22 projecting through and snugly fitting an aperture in the respective member of the ladder and retained in place by an appropriate head 23 swaged or pened thereon. The extension 22 is reduced to provide an annular shoulder at the respective terminus of each rod 18 so as to insure against lateral play relative to the engaged member, and, to increase the bearing, washers 24 may be provided between the shoulder on the one hand and the head 23 on the other, and the intei-posed web of the respective member of the ladder. The end portion of each rod 18 is bent to form an extension 18" of a length equal approximately -to the width v of the flange of the respective engaged member of the ladder for enabling the rod to reach the web of such member while leaving the brace made up of the two rods 18 free for pivotal movement relative to the legs 4 and the side bars 1.

It will be observed that the pivots 21, as best seen in Figure 1, are aligned at one side of the vertical plane of the pivots 19, and the pivotal connections 20 are aligned at the opposite side of the vertical plane of pivots 16, so that pivotal movement of the brace made 4up of lbars 18 as an entirety is eccentric to pivotal movement of the leaves 15 on the pivots 16. This eccentric movement causes the pivots 2O to describe a greater arc when swinging to and from a collapsed position than would be described by them if thepivots 21 and 19 or 16 were concentric, whereby the brace made up of the rods 18 effectively resists any collapsing stress and prevents accidental closing of the legs 4 on the bars 1, while the ladder is in use. When it is desired to collapse the parts, they may be caused to swing readily to the position indicated in dotted'lines in Figure 1 by merely elevating the legs 4, so as to leave them free to swing downward and toward the side bars 1. The incapacity of the legs 4 to swing downward while the ladder. is 'in use effects a relative locking action of: the ivoted parts, so that the brace made up of t e rods 18 is very effective in retaining the parts in their roper positions during use.'

As all) parts of the ladder are designed and adapted for construction of metal, the ladder adapts itself readily to a finish, such as white enamel or the like, which facilitates perfect cleansing and insures sanitation.

What is claimed is 1. A ladder comprising side bars, a tread connecting the same, legs articulated tothe sidel bars at the upper ends thereof to swin relative to the legs from an' open to a co apsed position, and a brace formed of rods connected together and having end portions pivotally' and permanently engagmg the legs and side bars for swinging to and from the collapsed position and for resisting opening. movement beyond a normal open position and for at the same time resisting lateral spreading stresses on the bars and legs. v

2. A ladder comprising side bars of channel irons, a tread connecting the side bars, hinges connected to the side bars at the end portions thereof, a leaf of each hinge being free for pivotal movement relative to the side bars, channel iron legs pivoted to the last-named leaves, anda plat orm of sheet metal fixed to the last-name leaves and having a marginal flange surroundin the hinges and the upper end portions 0% allel to the legs and side bars when collapsed with the marginal flange disposed at one side of the legs.

3. A ladder comprising side bars, a tread connecting the side bars, legs, a platform pivotally connecting the legs to the side bars, and a brace pivoted to the side bars and legs in vertical planes outside .the plane of the pivotal connection, the brace being formed o f crossed rods each bent laterally at each end portion and formed with a reduced extension projecting 'through the respective side bar or leg for formin pivotal connection therewith, and said race being adapted to remain pivotally connected to the legs and side bars as they are collapsed u on each other incident to pivotingl relative to the platform.

4. A ladder comprising side bars, a tread connecting the side bars, legs, a platform pivotally connecting the legs and side bars, said legs and side bars being formed of channel iron each facing inward, and a swinging brace extending on an inclined plane from the side bars to the legs and formed of crossed rods each bent at each end portion and extending laterally a distance greater than the width of the channel of the respective engaged member and through the web thereof for forming a permanent pivotal connection.

In testimony whereof I aix my signature.

HEYMAN ROSENBERG.

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