US2623679A - Nonslip ladder base - Google Patents

Description

Dec- 30, 1952 E. D. AGOMBAR ET AL 2,623,679

NONSLIP LADDER BASE Filed March 13. 1952 Patented Dec. 3Q, 1952 UNITED STTS NNSLP LADDER BASE Application March 13, 1952, Serial No. 276,298

(Cl. 22S-64) 3 Claims. 1

This invention relates to a ladder.

More particularly, the invention relates to a non-slip ladder.

The objects of this invention, generally, are to improve on known non-slip ladders.

A specic object of the invention is to provide a non-slip ladder in which a non-slip device is pivotally mounted to the ladder to be releasably locked in two operative positions, selectively.

Another specific object of the invention is to provide a non-slip ladder in which a device is releasably locked in two operative positions, selectively, to present spikes or shoes to the ground.

Another specic object of the invention is to provide a ladder in which there is provided a nonslip device of simple construction and easily attachable to the ladder proper, more particularly, to the runners of the ladder.

In the drawing, wherein like numerals of reference indicate corresponding parts in the various figures,

Figure l is a fragmentary side elevation of a ladder having a non-slipping device according to this invention, the device being shown in one of its two operative positions;

Figure 2 is a view similar to Figure l, but'wlth the device in its other operative position;

Figure 3 is a front elevation of Figure l, parts being broken away; and,

Figure 4 is a fragmentary end view of a modied form of the non-skid device.

Referring now by numerals to the drawing, L shows a typical ladder of which R are the two parallel runners and G, spaced rungs. The device, shown in its entirety as D and forming a complete pre-assembled unit, is pivotally connected to the runners as at and by pins or bolts I i.

The unit will now be described.

I2 are two members, similar in construction, each having a shoe I3 pivotally mounted at one end as at and by a bolt or pin i5. The end of the member I2, remote from the shoe, is formed to present a spike I4.

The members assume two operative positions; in one position, the spikes l t are presented to the ground (see Figure 2) and in the other position, the shoes I3 are presented to the ground or floor (see Figure 1).

In practice, the unit is rotated to position the shoes I3 adjacent the lower ends of the runners of the ladder, as when the ladder is to be used on a floor or other relatively smooth surface; when the ladder is to be supported upon the ground, the unit is rotated to position the spikes I4 adjacent the lower ends of the runners so that the spikes can dig into the ground.

As shown, the member l2 is formed with two similarly shaped plates I t each formed at one end with an apertured lug or ear Il. The ends of the plates, adjacent the lugs il, are connected together as by a bridge member I8, the bridge member conveniently being welded to the two plates. A ferrule or distance piece ISA preferably is used on the bolt i5 between the lugs 39.

The opposite ends of the plates It are bent inwardly as at le to engage one another, where they are butt welded together. The bent portions I 9 carry or are shaped to form the spikes I d aforesaid. The inwardly bent portions I9 from which the spikes extend serve as a ground-engagsurface which limits the penetration of the member into the ground, while permitting the spikes to dig into the ground.

rlhe distance between the plates I6 of the mem ber l2 preferably is slightly more than the width of the runner. The runner is thus housed Within the member I2 and relative displacement of the member on the runner, laterally thereof, is limited; and the stress imposed on the pins I I is merely one in shear.

A ferrule or distance piece et is preferably press-fitted through the runner to form a bearing for the pin II.

The two members I2 are rigidly connected together to turn as a unit on the axis of the pins Ii-i i, as by a transverse tube or pipe `2l) butt welded at its opposite ends to the adjacent plates it of the members I2, respectively. A shallow substantially V-shaped brace or bar 2l is welded at its opposite ends to the adjacent plates I E and welded to the tube 2t. The brace aids in retaining the two members i2 in parallelism at all times, especially when under load.

As shown, the shoe I3 is formed with a ilat member 22 from which rises aperturecl lugs 39. The shoe is pivotally connected to the ears or lugs Il as by the bolts I t aforesaid. Thus, the shoe is free to rotate on the member I2. To the underside of the flat member or foot 22 of the shoe is secured a grooved pad 23 of, say, rubber or such material as oifers good friction to the surface upon which the ladder rests.

Releasably to lock the unit in one or the other of its two operative positions, a locking device is provided. As shown (see Figure 3), bolts in the form of rods 25 are slidable within the tube 20. The bolts carry knobs in the form of screws 2l projecting through elongated slots 29 formed through the wall of the tube. Each bolt is urged outwardly toward a runner by a coil spring 30 tensioned between the inner end of the bolt and an abutment or dividing pin 3l secured in the 3 tube 2Q mid-length thereof. The engagement of the knob 2l with the outer end of the slot 29 determines the outermost (or locking) position of the bolt.

The bolt, when in its extended or operated position, extends into a keeper in the form of a bracket 33 secured to the runner, on the underside thereof, and preferably through both side plates I6 of the member I2, through apertures S5, releasably to lock the unit in one of its operative positions (see Figure l) at this time presenting the shoes to the ground.

Releasably to lock the unit in the other operative position, that is, to present the spikes to the ground (see Figure 2), the unit is so rotated on the axis of the pins II--II that the bolts 25 register with apertures 35, passing preferably through the runner. The arrangement is such that the bolts 25 are in eiiective register with the keepers 33 when the bent-in portions I9 o the members I2 engage the keepers, and the bolts are in register with the apertures (not shown) through the runners when the bridge members I8 are in engagement with the wear plates 36. The weight of the ladder on the pins II-II tends to rotate the unit anti-clockwise, when the unit is in the position shown in Figure l; such rotation is prevented by the bolts 25 when engaged in the keepers 33.

When the unit is in the position shown in Figure 2 (the bolts 25 now passing through the runners), the weight of the ladder also tends to rotate the unit anti-clockwise; such rotation is prevented by the engagement of the bridge members I3 With the Wear plates 36, rather than by the bolts, so that no crushing force is imposed upon the wood of the runners by the` bolts.

Preferably, the adjacent ends of the slots 29 are formed with notches 62, so that the bolts 25 may be releasably locked in their inoperative or withdrawn positions as when the unit is being rotated on the pins II-II from one position to its other operative position.

In the modified form shown in Figure 4, Ya plate lili is welded to the member I9 extending between the plate I5, and the spike MA is adapted to be removed when Worn. Thus, the spike includes a threaded shankreceiving two lock nuts 38.

What we claim is:

l. In combination with a ladder including two runners; a pair of members each formed at one end with a portion forming a ground-engaging surface and with a spike projecting from said surface to dig into the ground, a shoe pivotally mounted to the opposite end of each of said members and providing an anti-slipping surface,

means pivotally mounting said members to a lower portion of said runners to permit bodily rotation of said members between two operative positions to position said shoes or said spikes below said runners, selectively, and means for releasably locking said members in either of said two operative positions.

2. In combination with a ladder including two runners, aligned apertures through said runners and anchoring brackets; a preassembled antislipping device pivotally mounted to said runners, said device comprising a pair of members each formed at one end with a ground-engaging portion and with a spike projecting from said portion to dig into the ground, means rigidly connecting said members to rotate as one, a shoe pivotally mounted to each of said members adjacent th'e end thereof remote from said spike, saidV members being so formed and so mounted on said runners that said members position said shoes, or said spikes below said runners when in one or the other of two operative positions, and means including rods spring urged toward said runners to engage in said apertures or in said anchoring-brackets, releasably to lock said members in one or the vother of their two operative positions, selectively.

3. In an anti-slipping ladder including a pair of substantially parallel runners, a pair of members pivotally mounted to lower portions of said runners, each of said members being formed at one end with a at portion providing a groundengaging surface and with a Vspike projecting from said portion adapted to dig into the ground, a shoe pivotally mounted on the opposite end of each of said members providing an antislipping element, said members being so formed and mounted to said runners that they position said shoes .or said spikes below said runners when in one or the other of two operative positions, means rigidly connecting said members to rotate as. a unit, and means including springloaded boltsco-operating with said runners releasably locking said members in one or the other of their operative positions, selectively.

' EDWARD DAVID AGOMBAR.

ARTHUR BENJAMIN .AGOMBAR REFERENCES CITED The following references are of record in the le of this patent:

` FOREIGN PATENTS Number Country Date 17,499 Great Britain July 28, 1909 337,341 Germany May 31,1921

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