US3517772A

US3517772A - Folding ladder

Info

Publication number: US3517772A
Application number: US819693A
Authority: US
Inventors: Albert Weis; Baldwin E Petry
Original assignee: BALDWIN E PETRY
Current assignee: BALDWIN E PETRY
Priority date: 1969-04-28
Filing date: 1969-04-28
Publication date: 1970-06-30
Anticipated expiration: 1987-06-30

Description

June 3o, 1970 A. WEISV Em. 3,517,772

FOLDING LADDER Filed April 28, 1969 Sheets-Sheet 1 fue 5p /|4 5ol [I6 ,lo Mdm #Ezmf'j 1 2 :0 ne fo 22 my 24m@ 1&2 |80 6 y i500 |5IO 2 O .286 70 2 weg 22 @so /NVENTORS.

ALBERT wE/S ILT/G5 AND Ig BALDw/N EPETRY ydya United States Patent 3,517,772 FOLDING LADDER Albert Weis, 4825 Meredeth Ave., Lincoln, Nebr. 68506, and Baldwin E. Petry, Rte. 1, Box 1, Hockley, Tex.

Filed Apr. 28, 1969, Ser. No. 819,693

- Int. Cl. E06c 1/383 U.S. Cl. 182-163 8 Claims ABSTRACT OF THE DISCLOSURE A folding ladder comprising a plurality of sections at least two of which are hingedly connected and in which lock means is provided for maintaining the hinged sections in alignment, the lock means releasable for folding, the ladder being extensible.

FIELD OF THE INVENTION This invention is in the field of folding ladders and collapsible and extensible ladders.

DESCRIPTION OF THE PRIOR ART SUMMARY OF THE INVENTION A folding ladder having two adjacent sections the Stiles of which are interconnected by hinge assemblies, each hinge assembly comprising a bridge member extending across the adjacent ends of the respective adjacent aligned stiles, each hinge means further comprising a pair of y parallel pivot pins extending at approximately a right angle to the stiles, the pins of a pair being so spaced as to permit the adjacent stiles to be folded into parallelism with each other, one of the stiles of an adjacent pair having an extension rigidly connected thereto and extending beyond the point of connection of the respective hinge pin with that stile, whereby when a pair of adjacent stiles are in alignment, said extension laps the adjacent stile, and a releasable securing means interconnecting the extension of one stile with the lapped part of an adjacent stile so as to hold the adjacent stiles in alignment, the securing means being, more specifically, aligned openings in lapping portions of the stiles and a securing pin removably disposed through the aligned openings, and means for maintaining the pin in the openings.

The combination in which the means for attaching .the securing pin comprises an elongated rocker lever having fulcrurn means and having resilient means for continually urging the lever into a position for holding the securing pin in the openings.

The new` ladder has the advantage that the bridge member can be disposed at times transversely to a pair of sections when the sections are folded in parallelism with each other.

The combination described in which a ladder section has pintle-receiving socket means on the ends of its stiles and in which an adjacent ladder section has projecting pintles adapted to be respectively received in the socket portions described, and further in which releasable locking means is adapted to engage and hold the pintles to the adjacent ladder section to prevent their removal except when released as desired.

BRIEF DESCRIPTION OF THE DRAWING FIG. l is a side elevation of a folding ladder of this invention shown in completely extended position.

FIG. 2 is a side elevation of the ladder of FIG. l shown in the collapsed position.

FIG. 3 is a detailed sectional view taken along the line 3--3 of FIG. 1.

FIG. 4 is a detail showing the end of one of the stiles With -a bridge member removed.

FIG. 5 is a sectional view taken along the line 5-5 of FIG. 3.

FIG. 6 is a top plan view of the ladder when it is lying horizontally in an extended position.

FIG. 7 is a side elevation showing a hinge assembly and adjacent ladder sections with the sections shown in a position of inclination with respect to each other.

FIG. 8 is aside elevation of a modication of the ladder of FIG. l in which one of the sections is attached to the other by a pintle and socket at each stile.

FIG. 9 is a side elevation of the ladder of FIG. 8, but showing two of the sections in a folded position of parallelism and the third section disconnected.

FIG. 9A shows the disconnected section in top plan view.

FIG. 10 shows the top plan view of horizontally disposed ladder sections with only end portions showing and the remainder broken away, the sections being pintle and socket sections shown in disconnected position.

FIG. 1l is a side elevation of two end portions of sections having pintle and socket assemblies respectively.

FIG. 12 is a sectional view taken along the line 12-12 of FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The folding ladder of this invention is generally indicated at 10 in FIG. 1 and comprises a plurality of

sections

12, 14, and 16.

In FIG. 6 it will be seen that each of the

sections

12, 14, and 16 has two spaced parallel longitudinal

elongated stiles

20, 22, and 24. The stiles are connected by transverse step means 40.

Adjacent sections are interconnected by hinge means generally indicated at 50 comprising a bridge member 52 exending across adjacent ends of the respective aligned sti es.

Each hinge means 50 preferably comprises a pair of parallel pivot pins 62 extending at approximately a right angle to the stiles.

Each of the pivot pins 62 of a pair is pivotally connected to a different one of the adjacent ends of a pair of aligned stiles, for example, the

stiles

22 and 24\of FIG. 3. The pins of a pair are so spaced as vto permit the adjacent stiles to be folded into parallelism with each other, as shown in FIG. 2, and at such times, the bridge members 52 are disposed transversely of the stile.

One of the stiles of an adjacent pair of stiles of two separate sections is shown, for example, at 24 in FIG. 3, and will be seen to have an extension 70 disposed along an inner side thereof and secured thereto'and projecting beyond the end 74 thereof so as to lap the adjacent stile which is, for example, the stile 22 of FIG. 3, which latter has a removable securing member associated therewith and which interconnects the extension of one stile, as shown at 70, withvthe lapped part of an adjacent stile so as to hold the

adjacent stiles

22 and 24 rigidly in alignment.

Securing member 100 forms a part of a releasable securing means which further comprises aligned open-A 3

ings

120 and 126 in the stile 22 of FIG. 3 and in the extension 70 seen in FIG. 3, the

openings

120 and 126 extending transversely of the stiles.

The securing means 110 further comprises a lever 160 which can be called an elongated rocker lever extending longitudinally of one of the adjacent stiles, for example, the stile 22 in FIG. 3. The lever 160 is attached at one end to the securing pin 100, and fulcrum means 164 is attached to the lever 160 and disposed between it and that web 166 of the stile 22 which is on the opening 120 side of the lever 160, whereby the pin 100 end of the lever 160 is normally urged toward the extension 70 by a resilient means generally indicated at 180 comprising a spring 182 connected to the pin 100 section of the lever by means of a connector 188.

The spring 182 extends through a spring receiving opening 1500 in the web 66 of that stile 22 which is adjacent the connector 188, and the spring 182 is a coiled spring extending into a hollow transverse step means 1510 disposed in alignment with the spring receiving opening 1500 so that the coiled spring 182 can expand and certain portions can move through the opening 1500 as the pin 100 moves into the dotted line release position shown in FIG. 2.

The lever 160 is maintained in alignment by a screw 200 having a loose-fit through the lever 160 by extending through a hole 210, the screw 200 having a head 212 on the outer side of the lever 160 and the inner end of the screw is threadedly secured at 230 to the web 166 of the stile 22.

Referring now to FIG. 4, it will be seen that that terminal end 250 of the stile, for example, stile 22, which faces an opposite stile after the two have been disposed alongside each other in parallelism by folding, as seen in FIG. 2, it is cut away so as to have its terminal surface 252 inclined so that the endmost portion of the stile is of a lesser dimension. This is so that the end 250 of the stile 22 will not bump the end 74 of the stile 24, as seen in FIG. 3, at times when the two are folded about their respective hinge pins 60.

Referring now to FIG. 5, it will be seen that when the extension 70 moves into a lapping relationship with the opposite stile 22, it will be received between the outer wall 280 of a retainer 282 and the adjacent stile 22. The retainer 282 has its outer wall connected to the remainder of the stile by means of an end wall 286 of the retainer 282, whereby a slot 290 exists between the outer wall 280 and the stile 22. This has the effect of preventing the hinging of adjacent sections beyond the point in which the extension 70 of one section has entered the slot 290 of another so far as to engage the end wall 286.

Each extension 70 has a beveled edge portion 300, best seen in FIG. 7 and 'shown in dotted lines in FIG. 5, disposed alongside its opening 126 and facing the opposite stile 22 so as to tend to cause an end of the pin 100 to be deflected outwardly toward the dotted line position of the lever 160 shown in FIG. 3.

The head 212 of the screw 210 is in a particular position. It tends to hold the pin 100 from entering the slot 290 beyond the point where it is positioned to retain the extension 70. This tends to leave the innermost position of the pin 100 such that its end is spaced from the side wall 280 of the slot sufficiently to permit the sharpened edge 300 of the extension 70 to knife therebetween and deflect the pin 100 back through the web 166 of the respective stile 22 to a suicient extent to allow the extension 70 to pass. In this way, securing assembly 110 operates automatically whenever ladder sections are swung into alignment with each other because of an automatic locking.

vWe refer now to FIG. 8 in which a modified form of the ladder is there shown at 400 having a section 416 connected to adjacent section 418 by a hinge means gener- 'ally indicated at 450, but which is the same as the hinge means 50, the associated securing being done by a lever 460 and the associated securing means 500, which latter is the same as the securing means of FIG. 3.

The ladder of FIG. 8 further has a section 520 which is best seen in FIG. 9 which has a pintle 524 protruding from it and adapted to be received in a socket 530 of au opposite stile of the center section 418, and there are two pintles 524, one on each of the Stiles 528 of the section 520 and there is a socket 530 on each of the stiles of the section 418, as best seen in FIG. 10, adapted for the reception of the respective pintles `524.

The stiles of ladder section 520 each have a hilt 570 disposed inwardly of the respective pintle for effectively supporting the stile 520 on the end of the socket 530 of the adjacent stile 418.

As best seen in FIG. 11, the socket 530 is formed by having a plate 532 extending across from one flange to the other of the channel-shaped stile 418, whereby the pintle 524 is received inbetween the plate 532 and the web 540 of the stile.

Moreover, the pintle 524 when completely inserted extends beyond the plate 532 sufficiently to dispose a hole 600 extending transversely through the pintle 524 in a position for alignment with a securing pin 700 of a securing means or assembly 710, whereby the pin 700 can extend through the pintle 524, as best seen in FIG. 12, the pin 700 extending through the hole 600, which latter extends through a narrow portion 760 of the pintle which is disposed outwardly of a thicker portion 764 of the pintle, which latter snugly but slidably is received in the inside of the respective socket `530 inbetween the plate 532 in the webs 540. Securing means 710 operates in a similar fashion to the securing means 110 and it has a lever 762 similar to the lever 160. `It further has a fulcrum 764 similar to the fulcrum 164, a resilient urging means 780 similar to the resilient urging means connected by a connector 788 to the lever 762. A screw 800 has a head 812 on the outer side of the lever 762 and the screw 800 extends through the wall of the loosely fitting opening 880 in the lever 762. The inner end of the screw is secured at 900 to the stile 418, which in FIG. 12 is on the left, although in FIG. 1l it is on the right.

A guide groove 1000 extends from an end of the pintle 764 to the hole 600 for guiding the end of the pin 700 through the groove 1000 to the hole 600.

In FIG. 12 it will be seen that the position of the head y812 and the screw 800 is such as to hold the pin 700 such that its normal innermost end extends inwardly only enough to be engaged by the inclined innermost lwall 11010 of the groove 1000, whereby upon inserting a pintle ladder section 520 into the socket ladder section 418, the innermost ends of the pins 700 first strike the inclined bottom surfaces 1010 of the grooves 1000, which latter incline toward the lever 710 the farther inwardly of the pintle 524 since the pin 60'0 moves with respect to the pintle. When a pin is opposite the hole 600., it then drops in. Although it does not extend very far into the hole 600, it does extend enough to form a securing that is strong since the spring 780 is firm in holding the very short pin 700y in place.

Referring to FIG. 5, it will be seen that the bridge members 52 have inclined sides 1050v of the same inclination as those inner sides 1060 of the flanges of the channel-shaped ystiles which they engage to give a sliding but sung t and to prevent looseness, such flanges lbeing seen at 1070 in FIG. 5. The ends of the bridge members 52 are likewise slanted, as shown at 1090 in FIG. 3, inwardly toward the end of the respective stile as the web 166 of the respective stile is approached in order that when the bridge members are in the transverse position of FIG. 2, the end surfaces 1090 will firmly but slidably engage the inclined surfaces 1060 of respective stile flanges 1070.

What is claimed is:

1. A folding ladder comprising a plurality of sections each having two spaced longitudinal elongated stiles having inner sides connected by transverse step means, said sections being at times disposed end-to-end with their stiles in alignment respectively, hinge means connecting adjacent ends of said aligned stiles, each hinge means comprising a bridge member extending across the adjacent ends of the respective adjacent aligned stiles, said hinge means further comprising a pair of parallel pivot pins extending at approximately a right angle to said stiles, each of the pivot pins of a pair being pivotally connected to a dilerent one of the adjacent ends of a pair of aligned stiles, the pins of a pair being so spaced as to permit said adjacent stiles to be folded into parallelism with each other, one of the stiles of an adjacent pair having an extension rigidly connected thereto and extending beyond the point of connection of the respective hinge pin with that stile, whereby when said one stile is one of a pair of adjacent stiles Iwhich are in alignment said extension laps the adjacent stiles, a releasable securing means interconnecting the extension of one stile with the lapped part of an adjacent stile so as to hold the adjacent stiles in alignment, the securing means described comprising having aligned openings in the lapping portions of said extension of said one stile and in said adjacent stile, said aligned openings extending transversely of said aligned stiles, a securing pin removably disposed through said aligned openings, and securing means comprising a resilient means comprising a spring resiliently urging said securing pin into position for extending into both of said aligned openings.

2. The combination of claim 6 in which said extension is disposed on an inner side of the respective stile.

3. The combination of claim 1 in which said spring is a coiled spring, one of said transverse step means being hollow, and one of the stiles to which said one transverse step means is attached having a spring receiving opening therethrough through which portions of said spring can move as said spring is extended, and said coiled spring extending into said hollow transverse step means and through said spring receiving opening.

4. The combination of claim 1 in which said stiles are of channel shape and with the elongated recess of each stile facing outwardly away from said step means, and said resilient means being positioned on said ladder inwardlyof the outer side of the respective stile so as to use the elongated recess of the channel-shaped respective stile to receive portions of said resilient means.

5. The combination of claim 1 in which said means for attaching said securing pin removably in said aligned opening comprises an elongated rocker lever extending longitudinally of one of said adjacent stiles, said lever being attached at one end to said securing pin, fulcrum means between a central section of said lever and the adjacent stilt, resilient means operatively correlated between said lever and said adjacent stile for continually urging said lever into a position for disposing said securing pin in said openings.

v6. The combination of claim 1 in which one of the section of said ladder is provided with socket means on ends of the respective stiles thereof which are opposite the bridge member, and a further ladder section having two stiles each of the stiles having projecting pintles extending outwardly from terminal ends of the stiles, said pintles being removably received respectively in the sockets of au adjacent stile at times when the pintle and socket stiles are disposed in parallelism, and means releasably securing said pintle and socket stiles together to maintainrsaid pintles in said sockets.

7. The combination of claim 6 in which each of said pintles has a hole extending transversely therethrough, and in which the stiles having said sockets are provided with securing means thereon having latch means adapted to extend through openings in the stiles having sockets and also through the respective holes in said pintles for securing said pintles to the socketed stiles.

8. A folding ladder comprising a section having two spaced longitudinally elongated stiles having inner sides connected by transverse step means, said ladder section being provided with socket means on corresponding ends of its stiles, and a further ladder section having two stiles, each of the stiles of the further ladder section having projecting pintles extending outwardly from terminal ends thereof, said pintles -being removably receivable in the sockets of the first-mentioned stile at times when said lirst-mentioned section and said yfurther section are disposed in parallelism and means releasably securing the stiles having said pintles and the stiles having said sockets together to maintain said pintles in said sockets, and in which each of said pintles has a hole extending transversely therethrough, and in which the stiles having said sockets are provided with securing means thereon having latch means adapted to extend through openings in the stiles having sockets and also through the respective holes in said pintles for securing said pintles to the socketed stiles.

References Cited UNITED STATES PATENTS 68,836 9/1867 Boyd 182-178 226,449 4/ 1880 Fuller 182-163 1,157,739 10/1915 Tyler 182--204 FOREIGN PATENTS 2,068 1/ 1894 Great Britain.

REINALDO P. MACHADO, Primary Examiner