US864044A - Ladder. - Google Patents

Description

PATENTED AUG. 20, 1907. H. H. THOMSON.

LADDER. APPLICATION FILED JULY 25, 1906.

- 2 SHEETS-SHEET 1.

ATTORNEYS PATENTED AUG. 20, 1907. H. H. THOMSON.

LADDER. APPLICATION nun JULY 25'. 1906.

2 SHEETS-SHEET 2.

INVENTOR z'bbard 72617202710012 A rromvsrs HIBBARD H. THOMSON, OF LAWRENCE, KANSAS.

LADDER.

Specification of Letters Patent.

Patented Aug. 20, 1907.

Application filed July 25, 1906. Serial No. 327,658.

To all whom "it may concern:

Be it known that I, Hnanann H. TnonsoN, a citizen of the United States, and a resident of Lawrence, in the county of Douglas and State of Kansas, have invented a new and Improved Ladder, of which the following is a full, clear, and exact description.

This invention relates to certain improvements in ladders, whereby the same may be supported in an upright position, irrespective of the inclination or unevenness of the ground upon which the ladder stands or the nature of the body against which the upper end of the ladder rests.

Reference is to be had to the accompanying drawings forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the figures. I

Figure 1 is an elevation of one form of my improved ladder; Fig. 2 is a side elevation of the form shown in Fig. 1; Fig. 3 is a cross-section on the line 33 of Fig. 2; Fig. 4 is a front elevation of a slightly modified form of construction; Fig. 5 is a side elevation of the form shown in Fig. 4; Fig. 6 is a section on the line 66 of Fig. 5; and Fig. 7 illustrates a modified form of the support for the upper end of the ladder.

My improved ladder comprises two ordinary side bars 1, 2, united by a plurality of rounds 3 secured therein in any suitable manner. The side bar 2 is composed of two members slidably connected together, whereby the length of the said side bars may be adjusted, while the lower ends of the two side bars are secured to a base member 4 adapted to rest upon the ground, and which is of a length considerably greater than the distance between the side bars. This base piece 4 is pivotally secured to one of the side members in any suitable manner, preferably as shown in Figs. 1, 2 and 4, namely, by cutting away a portion of the lower end of the side bars and inserting the base member therein and securing the two by a bolt 5. As the length of the other side member may be adjusted, it is evident that the distance between the lower ends of the two side members is variable, and in securing the second side bar to the base member it is necessary to provide a slot 6 in which the securing bolt may move.

The two members of one of the side bars may be secured together and held in any desired relationship, by any suitable means.

In Figs. 1 and 3 I have shown a band or strap 7 secured to the lower end of the side bar 2 and inclosing the extensible leg 8, while the second hand or strap 9 is secured to the side bar adjacent the upper end of the extensible leg, and encircling it; this band 9 carries a pin .10 passing through a portion of the band at right-angles thereto, and pivotally connected to the band by a rivet 11. This pin may be withdrawn from operative engagement with the extensible leg into which it normally enters, by means of the handle 12. The side of the extensible leg 8 coming in contact with the pin 10 and held in place thereby is preferably provided with a metal faceplate 13 having a plurality of perforations of a size to exactly fit the end of the pin 10. By perforating this face-plate rather than having the pin enter directly into the perforations in the leg member 8, the liability of said perforations becoming worn or the material between two adjacent ones being broken or worn away, is

eliminated.

The band 9 is preferably provided with a handle 14 adjacent the handle 12 of the pin, and carries a spring 15 adapted to hold the pin 10 in engagement with the perforated plate 13 of the extensible leg. The handle 14 is preferably at a distance of about 3% feet from the ground, and is normally used for holding the ladder when the same is moved from one position to another.

In setting the ladder down upon the ground the handles 12 and 14 are brought together, and the pin 10 thus brought out of engagement with the extensible leg 8, whereby the latter slides down until the ends of the base member 4 are in contact with the ground. When the ladder is in the position desired, it is only necessary to let go of the two handles 12 and 14, and the ladder is thus automatically held in its adjusted position. The operation of this improved adjusting means is very simple as it is unnecessary to manipulate any nuts, bolts, screws or clamps of any kind, other than the simple operation of letting go of the two handles 12 and 14.

A modified form of adjusting means is shown in Figs. 4, 5 and 6, wherein the face-plate 13 is curved outward from the side bar 2 and fits within a groove in the extensible leg, thereby serving to hold the two parts in aliuement. The handle 14 extends upward from the end of the leg and is provided with a perforation through which the pin 10 is free to slide. To operate the said pin, I provide a handle 12 between the handle 14 and the side member, which handle 12 carries the pin and is held in operative engagement by a suitable coiled spring. It will be noted that the operation of this modified form is fully as simple, and substantially the same as the operation of the form shown in Figs. 1 to 3 inclusive, as the handle 14 may be used for carrying the ladder when it is desired to move the same from one place to another.

By the use of the improved construction above described, it will be seen that the ladder may be supported in a vertical position at any and all times, irrespective oi the unevenness of the ground. Furthermore, as the supporting parts of the base 4 are substantially greater in area than the ends of the side bars, the ladder does not so readily sink into soft or muddy ground, while by providing a base member of a length greater than the 'width of the ladder, the liability of the ladder being tipped to one side is very materially reduced, thus making it of greater stability and permitting more freedom of action for the worker upon the ladder.

My improved ladder is particularly adapted for use in picking fruit from trees, and in this Work it is often found necessary to rest the upper end of the ladder in a crotch of the tree or against a limb extending at an objectionable angle, whereby only one of the upper side bars would be supported.

To further increase the stability of my ladder, I bend the two side bars together at their upper ends, and hold them in such position by a bolt 15, preferably provided with rounds upon its outer ends. At the extreme upper end I provide a pointed metal plate 16 standing at right angles to the plane of the ladder. By this improved construction it will be noted that the ladder may be supported at its upper end against a limb or in the crotch of the tree and as there is but one point of support the stability very materially increases, while the plate 16 prevents the ladder from slipping off a limb should the latter bend away when the worker mounts the ladder.

In Fig. 7 I have shown an attachment for an ordinary form of ladder, whereby the advantages of a single point of support at the top may be obtained. This attachment comprises two members 17, 18, adapted to be secured to the upper end of an ordinary ladder in any suitable manner, and provided with an elongated bolt 15, and pointed plate 16 as shown in the other modifications above described.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. A ladder, comprising two side bars, a base member pivotally connected to the lower end of one of said side bars and slidably connected to the lower end of the other side bar, and means for varying the length of one of said bars and holding it in its adjusted position.

2. A ladder, comprising two side bars, means for adjust ing the length of one of said bars, and a base member pivotally connected to the lower end of one of said bars and slidably connected to the lower end of the other bar, said base member having the under side thereof cut away to leave supports only at its ends, and the upper ends of the side bars being united together, whereby the ladder when in use is supported at but three points.

3. A ladder having two side bars, means for carrying the length of one of said side bars, a bolt securing the upper ends of said bars together, and rounds on the ends of the bolt.

4. A ladder having two substantially parallel side bars bent together at the top, a bolt extending through the two and having rounds on its ends, a projection from the side bars above the said bolt, and at an angle to the plane of the ladder.

5. A ladder comprising two side bars, one of said side bars being composed of two members slidably connected together, a plurality of bands secured to one of said mem bers and encircling the other member, a perforated metal plate secured to one member, a spring pressed pin mounted on the other member, and adapted for engagement with the perforations in said plate, a base pivotally connected to the lower end of one side bar and adjustably connected to the lower end of the other bar.

6. A ladder having two side bars, one of said bars having an extensible leg, a handle on said side bar adjacent the leg, and by which the ladder may be moved, and means carried by said side bar, adjacent the handle, and adapted to contact with the extensible leg to hold the latter in any desired position.

7. A ladder, comprising two side bars, means for adjusting the length of one of said bars, a base member pivotally connected to the lower end of one of said bars, and means carried by the other of said bars and slidable longitudinally of the base member for securing said side bar and base member together.

8. A ladder, comprising two side bars, a base member pivotally connected intermediate its ends to the lower end of one of said bars, and a leg carried by the other ofsaid bars and longitudinally adjustable in relation thereto, the end of said leg being secured to the base member inter-- mediate the ends of the latter, and longitudinally adjustable in relation thereto.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

HIBBARD H. THOMSON. Witnesses:

D. L. ROWLANDS, E. I CALDWELL.

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