US766385A

US766385A - Step-ladder.

Info

Publication number: US766385A
Application number: US19710604A
Authority: US
Inventors: Orrin Richardson
Original assignee: Individual
Current assignee: Individual
Priority date: 1904-03-08
Filing date: 1904-03-08
Publication date: 1904-08-02
Anticipated expiration: 1921-08-02

Description

No. 766,385. BATENTBD AUG. 2, 1904. O. RICHARDSON.

STEP LADDER.

APPLICATION FILED MAR. 8, 1904.

N0 MODEL.

UNITED. STATES Patented August 2, 1904.

ORRIN RICHARDSON, OF APILEGATE, CALIFORNIA.

STEP-LADDER- SPECIFICATIONforming part of Letters Patent No. 766,385, a ed A gus 2, 1904.

Application filed March 8, 1904. Serial No. 197,106. (No model.) i

To a, whom it 'nt/r/y concern.-

Be it known that I, ORRIN RICHARDSON, a citizen of the United States, residing at Applegate, in the county of Placer and State of (.lalifornia, have invented a certain new and useful Step-Ladder, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to step-ladders, the object in view being to simplify and improve the construction disclosed in Letters Patent No. 603,579, granted to me May 3, 1898, for improvement in step-ladders.

One of the principal objects of the present invention is to combine with a step-frame and the supportingleg therefor a supportingframe so connected with the step-frame as to support the lower end thereof a considerable distance above the ground or surface upon which the ladder rests, whereby the side bars or legs of the supporting-frame may be adjusted relatively to each other and to the stepframe for holding the steps always on a level and without necessitating any portion of the step-frame coming in contact with the ground.

Another object of the invention is to provide simple and effective means for equally and reliably adjusting the legs of the supporting-frame and holding the same securely in their adjusted position.

\Vith the above and other objects in view, the nature of which will more fully appear as the description proceeds, the invention consists in the novel construction, combination, and arrangement of parts, as hereinafter fully described, illustrated, and claimed.

In the accompanying drawings, Figure 1 is a perspective view of a step-ladder constructed in accordance with the present invention. Fig. 2 is an enlarged elevation of a portion of the ladder, showing the step-frame and supporting-frame, said view being partly broken out in section to illustrate the manner of adjusting the legs of the supporting-frame. Fig. 3 is an elevation similar to Fig. 2, showing the legs adjusted to a sidehill position.

Like reference-numerals designate corresponding parts in all the figures of the drawings.

The step-ladder contemplated in this invention comprises, essentially, a step-frame 1, a supporting-leg and a supporting-frame 3. The step-frame I is composed of side bars 4, connected at intervals by steps 5. The supporting-leg 2 is made of any suitable length and has its upper end bifurcated and pivot-' ally connected at 6 with the step-frame 1, preferably through the medium of a top or platform 7. The lower end of the step-frame is upheld at a suitable distance above the ground or surface upon which the ladder rests by means of the supporting-frame 3, with which it is connected, and as clearly illustrated in the different figures of the drawings.

The supporting-frame 3 consists of a pair of legs 8, which converge toward their upper ends and which are connected at points intermediate their lengths by means of an equalizing-lever 9. The lever 9 is fulcrumed centrally at 10 on a bar or strip 11, extending vertically and connected with a plurality of the steps 5 midway between the side bars 1 of the step-frame. The opposite extremities of the equalizing-lever 9 are pivotally connected at 12 with the legs 8 of the supporting-frame, so that both legs 8 are caused to move simultaneously and equally in opposite directions, one leg moving upward as the other moves downward.

The upper ends of the legs 8 are guided by means of a cross-bar 13, which is rigidly connected with the step-frame 1. Secured to the rear side of the cross-bar 13 are guides or

keepers

15 and 16 of different sizes, but each consisting, by preference, of a metal strap ofi'set intermediate its ends to form a loop, through which one of the legs 8 is adapted to be slid for the purposes of adjustment. Each leg 8 is further provided with a stop 17, preferably in the form of a pin, which by coming in contact with one of the keepers or

guides

15 and 16 limits the movement of the legs and prevents the upper extremities thereof from escaping entirely from the keepers. The keeper or guide 16 is made somewhat larger than the guide 15, so as to admit of a lateral movement of the leg 8, as illustrated by dotted lines in Fig. 2, and the offset portion of the keeper or guide 16 is crossed by means of a pin or bolt 18, which is adapted to be engaged by the teeth 19 of a rack or rack-plate secured to the face of the adjacent leg 8. Arranged at the outer side of the leg 8 and within the guide or keeper 16 is a cam 20, which may be swung upward or downward for the purpose of pressing the leg 8 inward or allowing the same to be swung outward, as illustrated, respectively, by the full and dotted lines in Fig. 2. When the upper end of the leg 8 is swung inward, the teeth 19 are brought into engagement with the pin 18 and caused to interlock therewith, thus holding both of the legs 8 against further sliding movement. By turning the earn from the full to the dotted line position shown in Fig. 2 the upper end of the leg 8 may be swung outward, as shown by dotted lines, thereby disengaging the teeth of the rack from the pin 18 and allowing both of thelegs to slide in either direction through the guides or

keepers

15 and 16. The method of adjusting the legs 8 is clearly illustrated in Figs. 2 and 3, Fig. 2 showing the legs adjusted for use on level ground and Fig. 3 illustrating the legs adjusted for use on a sidehill. It will be apparent that the position of the legs may be adjusted and regulated to suit a grade of any degree.

A'step-ladder constructed as above described is light, strong, and durable. The bottom of the step-frame is upheld at a considerable distance above the surface upon which the legs 8 rest and cannot therefore interfere with the adaptation of the ladder to a sidehill, the lower end of the step-frame being raised above all obstructions. To adjust the ladder, it is only necessary to turn the cam and disengage the rack from the pin 18, then pull or ush against the ladder until the step-frame assumes an upright position. When this is accomplished, the cam is again turned so as to cause an interlocked engagement between the rack and pin, whereupon the ladder is ready for use and is just as effectively supported and braced as if supported upon level ground.

Having thus described the invention, what I claim as new, and desire to secure by Letters Patent, is

1. A step-ladder comprising a step-frame, a supporting-leg pivotally connected therewith, and a supporting-frame comprising a pair of legs, an equalizing-lever connecting said legs with the step-frame so as to support the step frame above the ground, guides through which said legs slide, and means on one of the guides for admitting of the adjustment of the upper portion of one of said legs and fastening the same when adjusted, substantially as described.

2. A step-ladder comprising a step-frame and supporting-leg pivotally connected therewith, a supporting-frame consisting of a pair of legs, an equalizing-lever fulcrumed on the with, and a supporting-frame consisting of a pair of legs, an equalizing-lever fulcrumed on the step-frame and pivotally connected at its ends with said legs, guides or keepers for the upper portions of said legs, a pin connected with one of the keepers, a rack on one of the legs for engagement with said pin, and means for holding the rack and pin in engagement with each other, substantially as described.

4. A step-ladder comprising astep-frame,

a supporting-leg pivotally connected therewith, and a supportingframe consisting of a pair of legs, an equalizing-lever fulcrumed on the step-frame and pivotally connected with said legs, keepers or guides on the step-frame adapted to receive the upper portions of said legs, a pin connected with one of said guides, a rack on one of the legs adapted to engage said pin, and a cam for effecting an engagement between the rack and pin, substantially as described.

5. A step-ladder comprising a step-frame, a supporting-leg pivotally connected there with, and a supporting-frame consisting of upwardly-converging legs, an equalizing-lever fulerumed on the step-frame and pivotally connected with the lower portions of said legs,

a cross-bar on the step-frame, guides or keepers thereon receiving the upper ends of said legs, stops on the legs adapted to cooperate with said keepers, a pin connected with one of the keepers, a rack on one leg adapted to engage said pin, and a cam adapted to press the rack into engagement with the pin, substantially as described.

6. A step-ladder comprising a step-frame, a supporting-leg pivotally connected therewith, and a supportingframe consisting oi am