US874801A - Extension-ladder. - Google Patents

Description

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APPLICATION FILED .TUNE 28,1907.

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A w Q l HENRY C. SIEMS AND HEINRICH DEWITZ, OF WHEATLEY, ARKANSAS.

ExTENsIoNmADDER.

Specification of Letters Patent.

Patented Dec. 24, 1907.

Application filed June 28, 1907. Serial No. 381,265.

'HEINRICH Dnwirz, citizens of the United States, residing at Wheatley, in the county of St. Francis and State of Arkansas, have invented certain new and useful Improvements in Extension-Ladders, of which the following is a specification.

The present invention has for its primary object to provide an improved ladder which is peculiarly designed so as to be readily collapsed When not in use.

The invention further contemplates the provision of supporting members for the ladder which serve to hold the ladder in an upright position when extended and also form a truck to facilitate transportation of the ladder when folded. y

A still further object is to design a simple andefficient ladder of this character which can be utilized either as a step ladder or as an extension ladder according to circumstances.

For a full description of the invention and the merits thereof and also to acquire a knowledge of the details of construction and the me'ans for effecting the result, reference is to be had to the following description and accompanying drawings, in which:

Figure 1 is a perspective view of a ladder embodying the invention, the same being shown as extended. Fig. 2 is a similar view showing the ladder when folded. Fig. 3 is a perspective view showing the device when used as a step ladder. Fig. 4 is a detail view of one of the foot boards. Fig. 5 is an enlarged detail of one of the clamps by which the extensions are connected to the legs. Fig. 6 is a view of a portion of one of the sides of the ladder, showing a modification.

Corresponding and like parts are referred to in the following description and indicated in all the views of the drawings by the same reference characters.

In general the invention comprises a ladder in which the side pieces have a lazy tong construction and can be extended or collapsed as desired. Each of the sides of the ladder comprises a plurality of bars lwhich are pivotally connected at their ends as indicated at 2 and at their intermediate points upon the rods 3 constituting the foot-pieces or rungs of the ladder. Supporting bars 4 are pivotally connected to one set of the bars 2 at the lower end of the ladder, the end portionsof the bars being curved upwardly and connected by the rod 5. It will also be observed that a foot-piece or cross bar 6 joins intermediate portions of the supporting bars 4. Pivotally connected to the extremities of the opposite set of the bars 1 at the lower end of the ladder are the levers 7. These levers are also pivoted to the supporting bars 4 at 8 and are extended beyond the latter, the extremities of the levers being formed with the prongs 9 designed to engage the ground or other surface upon which the ladder rests in order to prevent slipping. Plates 10 are applied to these projecting ends of the levers 7 and a shaft 11 is journaled between the said plates, wheels 12 being mounted upon the shaft. When the handle portions of the levers 7 are swung upwardly and the footpiece 6 pressed downwardly the sides of the ladder are extended as shown in Fig. 1.

Each side of the ladder is provided with a transverse tie member 13 connecting corresponding ends of the bars 1, and a longitudinal tie member 14 connecting intermediate ortions of the bars 1, each of said tie memers having one end adjustably secured to the ladder whereby the lazy tong construction can be extended to any required degree and then rigidly locked in position. In the present instance these tie members 13 and 14 are in the nature of chains, a selected one of the links being designed to engage a suitable projection upon the ladder. A shaft 15 connects the extremities of one pair of the bars 1 at the upper end of the ladder and carries the rollers 16 which are designed to engage a wall or other vertical surface when the ladder is being extended against the same. When the ladder is folded as indicated in Fig. 2 the bars 1 of the lazy tong construction are collapsed against the levers 7 and the wheels 12 are lowered into engagement with the ground or other surface while the supporting bars 4 are swung outwardly so as to form suitable supports for the truck.

When in this position the ladder can be readily wheeled from place to place by grasping the handle portions of the levers 7 and lifting the curved ends of the supporting bars 4 away from the ground. It is also contemplated under certain conditions to utilize the device as a step ladder, and for this purpose the legs 17 are provided, the said legs being suitably connected by the diagonal brace members 18 and the transverse braces 19. Each of the legs 17 has an extension 20 and the said extensions are adjustably connected to their respective legs by the clamping members 21 which are in the nature of loops and have their inner faces roughened to prevent longitudinal slipping of the extensions after being properly adjusted. The lower portions of the extensions 20 are connected by a chain 22 and tie rods 23 are loosely connected at one end to the legs 17, the opposite extremity of each tie member being forked at 24 for engagement with one of the rungs 3 of the ladder, the two arms of the fork being designed to be connected by a pin as shown upon the drawings. The upper extremities of the legs 17 carry the spaced extensions 25 designed to receive the bars 1 at the top of the ladder, the said extensions being connected by pins 26 extending through the said bars. It will thus be seen that these legs 17 are detachably connected to the ladder and are extensible so as to be adjusted to conform to the degree to which the lazy tong construction is extended.

When the device is utilized as a step ladder it is designed to employ the foot boards 27 which are shown as formed in two hinged sections and provided at their extremities with the projections 28 designed to be received within corresponding openings 29 in the bars 1 of the lazy tong construction. By forcing the hinged central portion of the foot-pieces 27 upwardly so that the two sections of the board are disposed at an angle to each other, the projections 28 can beeither disengaged from or thrown into engagement with the openings 29, the foot boards 27 ben ing locked in position when the hinged central portions are pressed downwardly so that the two sections of the board are in alinement with each other.

From the foregoing description it will be readily apparent that the ladder can be readily transported from place to place owing to the truck formation produced by the levers 7 and supporting bars 4 when the ladder is folded. Furthermore the ladder is so constructed as to be quickly extended by a sinin the construction of the larger sizes of the ladders to provide the lazy tong construction of the sides with the lateral extensions 30 which serve to increase the strength of the device when used as a beam.

Having thus described the invention, what is claimed as new is:

1. In a ladder, the combination of collapsible' side pieces, foot pieces connecting the side pieces, and coperating levers and supporting bars pivotally connected to the side pieces of the ladder and to each other, one of said members carrying wheels and the said members cooperating to form a truck for the ladder when collapsed. ff

2. In a ladder, the combination of collapsible sides, foot pieces connecting the side pieces, cooperating levers and supporting bars pivotally connected to the side pieces of the ladder and to each other for controlling the collapsing of the side pieces, and means carried by the levers for coperation with the same and the supporting bars to form a truck for the ladder when collapsed.

3. In a ladder, the combination of side pieces having a lazy tong construction, footpieces connecting the side pieces, a lever pivoted to one end of the ladder, a wheel carried by the lever, and a supporting bar also pivoted to the ladder and coperating with the lever to form a support for the ladder when extended and a truck for the ladder when folded.

4. In a ladder, the combination of side pieces having a lazy tong construction, footpieces connecting the side pieces, a lever applied to one end of the ladder, a supporting bar applied to one end of the ladder, and a wheel carried by the lever, the lever vand supporting bar forming a trucli for the ladder when folded.

5. In a ladder, the combination of side pieces having a lazy tong construction, foot pieces connecting theside pieces, levers pivotally connected to the side pieces of the ladder, wheels carried by the levers, and supporting bars pivotally connected to the side pieces of the ladder and to the levers, the free ends of the supporting bars being curved outwardly and connected by a rod upon which the foot is placed when extending the ladder, the said levers and supporting bars cooperating to form a truck for the ladder when collapsed.

6. lIn a ladder, the combination of side pieces having a lazy tong construction, foot pieces connecting the side pieces, supporting bars pivotally connected to the side pieces of the ladder, levers pivotally connected to the side pieces of the ladder and to the su porting bars, the said levers being provided with prongs for engaging the surface upon which rying projectionsv adapted to enter the betlle ladder rests to prevent slipping, and fore mentioned sockets. Wheels mounted upon the leversI the said le- In testimony whereof We affix our signa- ;fers and supportkilng1 alrs coperaltling o ture in presence of tWo Witnesses. 5 orm a truck for t e a er when co a se I 7. In a ladder, the combination ofpside S-gzvsrz L' S'l pieces comprising a plurality of pivoted bars J L" S'- `forming a lazy tong construction, said bars Witnesses: being provided with sockets, and removable SOPHIA SIEMS,

1.0 foot boards comprising hinged sections ear- CHRIST SARToRrUs.

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