US1169700A

US1169700A - Adjustable step-ladder.

Info

Publication number: US1169700A
Application number: US85867514A
Authority: US
Inventors: Charles S Waltower
Original assignee: Individual
Current assignee: Individual
Priority date: 1914-08-26
Filing date: 1914-08-26
Publication date: 1916-01-25
Anticipated expiration: 1933-01-25

Description

C. S. WALTOWER.

ADJUSTABLE STEP LADDER.

APPLICATION FILED AUG.26. 1914.

2 SHEETS-SHEET I.

.4L 5;? 3f 54 ,58 I Q E m 57 I E- E gnvenfoz CSWa/iower Witneoom m C. S. WALTOWER.

ADJUSTABLE STEP LADDER.

APPLICATION FILED AUG.26. 191.4.

Patented Jan. 25, 1916.

2 SHEETSSHEET 2- "more s rens PTNT clarion CHARLES S. WALTO'WEB, OF ENSLEY, ALABAMA.

ADJUSTABLE same-LADDER.

Application filed August 26, 1914.

To all whom it may concern:

Be it known that 1, CHARLES S.-WAL- TOWER, a citizen of the United States, residing at Ensley, in the county of Jefferson and State of Alabama, have invented certain new and useful Improvements in Adjustable Step-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 anpertains to make and use the same.

My invention relates to new and useful improvements in step ladders of the well known folding type and resides in the provision of a step ladder that is of simple construction and is adjustable so that it may be placed upon irregular and uneven surfaces such as stairways, roofs and the like, and have a firm footing.

Another object of importance is to provide a step ladder of the character described that is constructed with independently adjustable legs which may be readily locked in adjusted position and will permit of the use of the step ladder on stairways and other uneven surfaces.

Another object of importance is to provide a. step ladder of the character 'described that is provided with a number of auxiliary rungs that may be readily and easily put in the proper position when the legs of the ladder are extended from their normal position.

Another object is to provide a ladder of the character described that may be readily folded into compact form, is light and simple as to construction, reliable and efficient in operation and which can be cheaply manufactured.

The above and additional objects are accomplished by such means as are illustrated in the accompanying drawings, described in the following specification and then more particularly pointed out in the claims.

With reference to the drawings, wherein I have illustrated the preferred embodiment of my invention as it isreduced to practice, and throughout the several views of which similar reference numerals designate corresponding parts Figure 1 is a side elevation of my improved step ladder showing it placed upon a stairway or steps, Fig. 2 is a front elevation of my improved ladder showing it in use, Fig. 3 is a fragmentary enlarged vertical sectional view of the locking pawl and Specification of Letters Patent.

Patented Jan. 25, 1916.

Serial No. $58,675.

cooperating parts, Fig. 1 is an enlarged detall sectional view of one of the auxiliary rungs showing it attached to one of the legs of the ladder, Fig. 5 is a detail perspective view of the pivoted locking plate, Fig. 6 is a sectional view showing in plan the bracing means for the supporting legs of the ladder, and Fig. 7 is an enlarged detail view of one of the guides showing the manner of securing them to the legs.

Referring to the drawings by characters of reference, the numeral 1 designates as an entirety a step ladder of the ordinary construction, which consists of rung supporting legs 2 and supporting brace legs 3, arranged in pairs, and the usual rungs 4 mounted between the legs 2. The

legs

2 and 3 are hingedly connected with each other in the usual manner and a supporting tray 5 is operatively connected with the legs.

The outer faces of the

legs

2 and 3 are formed with ratchet teeth 6 or notched.

Slidably mounted upon the outer faces of the

legs

2 and 3 are sets of extension legs 7 1 and 8 respectively.

Secured upon each of the

legs

2 and 3 is a guide band or collar 9 that slidably receives the

legs

7 and 8 on each of the

legs

2 and 3. This band or collar 9 is formed wilth rolled cars 10 on its upper edge on one s1 e.

A small wire frame 11 is hinged as at 12 to the inner face of each of the

legs

2 and 3 and has its free ends disposed angularly as at 13 and positioned so as to extend in the outer ends of the ears 10 to hold the sleeve 9 in position.

Hingedly mounted as at 14: within openings formed adjacent to the upper end of the extension legs are pawls 15. Each of these pawls 15 is provided with an offset projection 16 at one end that is designed to cooperate with the teeth 6 on the legs of the ladder.

A leaf spring 17 is secured at one end to the extension leg and bears against the pawl 15- on each extension leg.

A bowed protector plate 18 is secured transversely on each of the extension legs and over the spring 17 so that accidental derangement of the spring is obviated.

Mounted upon the upper ends of the extension legs 7 and8 are guide sleeves 19 that are fixed to the extensions and are slidable upon the

legs

2 and 3 of the ladder. These guide sleeves partially surround the legs of'the ladder but it will be seen that the extension legs are rigidly braced and permitted free sliding movement.

Secured upon each of the pawls 15 is a latch plate 20 that is spaced at its upper edge from the pawl.

Pivoted as at-'21 to the extension legs are latch plates 22 that are bent on one side to provide a cam surface 23 and are formed opposite-with an extension which provides a handle .24:- This plate 22 is designed to be positioned between the extension and the latch plate so as to hold the pawls 15 out of operative engagement with the teeth 6 and to permit quick adjustment of the extension legs. The plates 22 are turned so that the cam faces 23 thereon are brought under the plate 20 thus forcing the pawls 15 out of position. 1

The extension legs 7 are provided with rows of elongated openings 25 arranged in pairsand opposed to one another. These Openings .25 are designed to receive locking pins 26 that are rotatably and slidably 'mounted upon the ends of auxiliary rungs 27. A plate 28 serves to rotatably secure the pins 26: upon the rungs. The outer ends of the pins 26 are bent approximately at right angles as at 29 and the inner ends of the pinsare bent to form handle loops 30. By inserting the pins through the openings 25 in the extension legs 7 and turning them so that the portions 29 will prevent withdrawal, the rungs 27 may be secured and supported in a reliable manner and any number of rungs dependent upon the height of the laddermay be'added.

As a means for bracing or strengthening the extension legs S'that are secured to the supporting legs 3 and slidable thereon I provide a brace designated 31 as an entirety and that'consists of a rectangular body plate 32-tl1at is of just-sufficient length to snugly engage the opposed faces of the legs 8 at their ends.- i

A rectangular plate 33 of greater length than the one 32 is carried upon the body plate 32 and engages the outer longitudinal edges of the legs 8.

Rectangular'locking plates 34: are hinged as at 35 to the outer ends of the plate 33 and are designed to be folded back upon the outer face of the plate 33 with their outer or free edges disposed adjacent to one another.

Pivoted locking the plate 33 serve to hold the locking plates 35 inlocked position. Rectangular plates 37 are hingedly secured by means of suitable hinges 38 upon the outer faces of the plate 35 adjacent to the inner or hingedends thereof. and are designed to fold to engage the outer faces of the legs 8. Approximately U-shaped clamps 39 are carried'upon the outer endof the plateifl. ToafiXthe brace conditions concurrent with plates 36 mounted upon 8. The plates 37 are hingedly connected with the inner ends of the plates 35. \Vlien the plates 35 are brought to rest upon the outer faces of the plates 33, the locks 36 are then moved into operative position and the clamps 39 are securely held in position.

In operation when it is desired to extend the

legs

7 or 8 so that the ladder is adapted for use in connection with steps or other uneven surfaces, the locking plates 22 are operated so that the cam faces 23 are moved. By grasping the extension legs and pulling grasping the extension legs and pulling downwardly thereon they may be moved into the desired adjusted position. The springs. 17 force the guards into cooperative engagement with the teeth 6 thus the extension legs are held against upward movement in various adjusted positions.

With reference to the foregoing description and accompanying drawings, it will be readily seen that I have provided a folding ladder wherein the legs are independently adjustable and the extension means therefor may be readily removed and as easily placed in position for the purpose of storage or shipment.

In practice, I have found that the form of my invention, illustrated in the drawings and referred to in the above description, as the preferred embodiment, is the most officient and practical; yet realizing that the the adoption of my device will necessarily vary, I desire to emphasize the fact that various minor changes in details of construction, proportion and arrangement of parts may be resorted to,when required, without sacrificing any of the advantages of my invention, as set forth.

What is claimed is 1. A step ladder of the character de scribed consisting of pairs of legs hingedly secured with one another at their upper ends and provided on their outer faces with rack teeth or notches, guide rings hingedly secured adjacent the lower ends of said legs on the inner face thereof, extension legs slidably mounted upon the outer faces of said first legs and through said rings and also provided with openings therein adjacent their upper ends, pawls hingedly mounted within the openings and arranged to engage the 1-ackteeth on the outer face of the first mentioned legs, spring means secured to the extension. legs tohold the paWls into cooperative engagement With the teeth or notches, means carried by the extension legs to hold the pawls out of engagement With the teeth.

2. A step ladder of the character described comprising pairs of legs hingedly secured With one another at their upper ends and provided on their outer faces With rack teeth or notches, guide rings positioned over the lower ends of said legs, means secured to the inner face of said legs and to the guide rings for holding the same in position, extension legs slidably mounted through the guide rings and upon the outer faces of said first legs, said extension legs having openings therein adjacent to their upper ends,

guide collars secured around the upper ends of the extension legs, paWls hingedly mounted Within the openings in their legs to engage the rack teeth on said first legs, spring means to hold the pawls into cooperative engagement With the teeth, means carriedby said extension legs for holding said paWls out of cooperative engagement With the teeth, said legs are slidable upon the first mentioned legs.

In testimony whereof I afiix my signature in presence of two Witnesses.

CHARLES S. WALTOWER. Witnesses:

A. D. SLYE, W'. R. STEWART.

Copies of this patent may be obtained for five cents each, by addressing the "Commissioner of Patents, Washington, D. C.