US2469559A

US2469559A - Ladder

Info

Publication number: US2469559A
Application number: US625378A
Authority: US
Inventors: Harold A Johns
Original assignee: IMAGINEERING CORP
Current assignee: IMAGINEERING Corp
Priority date: 1945-10-29
Filing date: 1945-10-29
Publication date: 1949-05-10
Anticipated expiration: 1966-05-10

Description

May 10, 1949.

H. A. JOHNS I LADDER Filed Oct. 29, 1945 j ik J Patented May 10 1949 LA ER:

of- Illinois arold A. Johns, Chicago, Ill assignor to Imagi; neer-ing Corporation, Chicago, Ill.; a corporation App ic ti n. October 29, .5 Seria NQ- 2 ,33

(01. gas-a9) 4 Claims. 1

This invention relates to a ladder. and more particularly to a ladder of a toldable type. The invention is particularly useful in connection with a foot ladder.

An object of the invention is to provide a ladder formed of relatively few parts and which may be readily folded into collapsed and expanded positions, cooperating parts in the top portion of the ladder serving to lock the structure together into a sturdy rigid support when in expanded position. A'further object is to provide a simple ladder structure which may be col p y s in e p eard. h dd r. and drawn to expanded position by merely moving the rails of the ladder forwardly. the top. board of the ladder serving not only as a handle for collapsing the ladder but also. when the lad-, der is in expanded position, serving to, lock the structure rigidly supporting position, Other specific objects and advantages will appear as the specification proceeds.

The invention is illustrated, in preferred embodiments, by the accompanying drawing, in wh h. a

Figure l is a side view in elevation of a ladder embodying m invention; Fig. 2, a View similar to Fig. 1 but s owing the ladder in collapsed position; Fig. 3, a rear view in elevation; Fig. 4, a top plan view; and Fig. 5., a rearview irrelevation of the. ladder equipped with a modified form of back support. In the illustration given, a pair of side rails 10 are connected by steps II and at their top engage a top board I2. A back support 13 is secured to the rear edge of the top board l2. Link members [4 connect the rails l0 and back support iii to limit the angle of separation thereof.

The side rails A may be formed of any suitable material and configuration. In the illustration given, the rail I0 is formed from a strip metal having rolled side edges l5 which provide tubular supports and the intermediate web portion is preferably provided with elongated openings 16 which lighten the rails. Between theslots l6 cleats 11, formed of hollow metal webbing, are welded to the web portion of the side rails II] or otherwise secured thereto. The steps H are also shown formed of strips of metal having rolled edges l8 providing cross beam supports and the members l8 are received within sockets provided by the cleats or step-supporting brackets IT.

The rails I!) are pivotally connected at their rear top edges at l9 to the top board l2.

The top board I2 is preferably formed of metal having a wide central web portion 20 and dependins flan es. 2 Th W b p r ion. 2% is p e a ly provided with ribs 22 or other suitable roughenl m If cle irfid. the forward corner pori ns of the web 2 nd n s 21. may be formed w resi ien s t portions 2.3v wh c a e, daptd t ric iona y en ag and. grip. he o w r t p portion of the rails I'll.

The back support. [3. may be of any suitable construstion. In the form shown in Figs. 1 to 4 ncl ive. t c pris s a uvshsned ba h vi i t o n p ota l qennectefd to the fl e Qfth r board. at 2.

Ph cosme ics of the back s p or 3 at 24 brings the back member in close relation to the flange 2|, so that flange 2| is useful in praviding rig i i su p t o the back port at its 209-.

To limit the angle of separation between the back support 13 and the rails Ill, I provide a link M which is pivotally connected to the back suprest t and t the rails t 2.6.-

The rails 10 may beprqvided at their base with rubber inserts g1 which prevent slipping of the rails, the inserts being secured within the tubu-v lar members l5 or many other way secured to the rails I0.

In he mQd fie qnstr etiq sh w in E the structure throughout is the same except for h back. suppo t. he. bac suppor wn in Fig. 5 comprises a pair cf members 118 having int rm d at po tions b wed inward a d secured et e a .9 b PQt W din belts or y o s er suitable means, the legs being sprung apart again at the bottom and provided with rubber bases 30.

In the operation of the structure, the ladder may be moved from the collapsed position shown in Fig. 2 to expanded position by merely drawing the rails l0 forwardly. This movement causes the top board l2 to drop to the position shown in Fig. 1 and the link l4 swings to the inclined position shown in Fig. 1. When the user steps upon the ladder, the ladder automatically locks itself rigidly by bringing the flange 2| tightly about the forward edges of the rails I0. If the sockets 23 are employed, the sockets, which extend well around the forward portion of each rail I0 firmly grip the rail and lock it rigidly to the top board l2.

After use of the ladder, the user may simply grasp the forward end of the board l2 and pull it upwardly. This movement causes the rails 10 to swing to the collapsed position shown in Fig. 2. The forward flange 2! serves, in these operations, not only as a locking element to provide the desired rigidity, but also as a handl for collapsing the ladder and carrying the collapsed structure. It will be noted that in this operation no other manual movement is necessary. Since the link M is a single member and is not formed of two pieces connected at their center, it is not necessary to brace the link in any manner.

While in the foregoing structure, I have set forth specific details which are favored because of the new functions developed, it will be understood that changes may be made such as, for example, substituting a two-link brace pivotally connected in the center for the one-link brace i4, and also other means may be provided for locking the rails to the top board instead of the specific structure shown. I prefer, however, the specific structure illustrated because of the new functions accomplished, the extreme rigidity automatically provided by the pressure of a person upon the step in causing the flanges at top !2 to grip the rails, and the ease with which the structure may be collapsed through simply lifting the forward flange of board 12.

The modified form of back support 23 is extremely sturdy and firm while employing a relatively small amount of metal. The structure is further desirable in that the diverging feet portions provide a means for self-centering the ladder when weight is put thereon.

While in the foregoing description, I have set forth certain details illustrating a particular embodiment of the invention, it will be understood that such details may be varied widely by those skilled in the art without departing from the spirit of my invention.

I claim:

1. A ladder comprising a pair of rails, step means connecting said rails, a back support, a top board having a web wider than said rails equipped with depending flanges, said flanges providing socket portions adapted to grip the forward top portions of said rails when brought thereagainst, means pivotally connecting the rear top portions of said rails to said flanges at an intermediate point on said board to permit said rails to swing within said flanges and bring the forward top portions thereof into engagement with said flanges and permitting said rails to swing rearwardly when the front portion of the board is raised, and means connecting the back support to the rear portion of said board.

2. A ladder comprising a pair of rails, step means connecting said rails, a back support, a

top board having a web wider than said rails and equipped with depending flanges, means con necting the rear top portions of said rails to said flanges at an intermediate point on said board to permit said rails to swing within said flanges and bring the forward top portions thereof into engagement with said flanges permitting said rails to swing rearwardly when the front portion of the board is raised, and means connecting the back support to the rear portion of said board.

3. A ladder comprising a pair of rails, step means connecting said rails, a back support, a top board having a web wider than said rails and equipped with depending flanges, said flanges being adapted to grip the forward top portions of said rails when brought thereagainst, means pivotally connecting the rear top portions of said rails to said flanges at an intermediate point upon said board to permit said rails to swing within said flanges and bring the forward top portions thereof into engagement with said flanges permitting said rails to swing rearwardly when the front portion of the board is raised, and means connecting the back support to the rear portion of said board.

4. A ladder comprising a pair of rails, step means connecting said rails, a back support, a top board having a web wider than said rails and equipped with depending flanges, said flanges providing resilient socket portions adapted to grip the forward top portions of said rails when brought thereagainst, means pivotally connecting the rear top portions of said rails to said flanges at an intermediate point on said board to permit said rails to swing within said flanges and bring the forward top portions thereof into engagement with said flanges permitting said rails to swing rearwardly when the front portion of the board is raised, and means connecting the back support to the rear portion of said board.

HAROLD A. JOHNS.

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

UNITED STATES PATENTS Number Name Date 1,555,483 Rosenberg Sept. 29, 1925 1,630,747 Johnson May 31, 1927 1,671,801 White May 29, 1928 2,15%,606 Covington Apr. 18, 1939