US2408372A

US2408372A - Ladder extension

Info

Publication number: US2408372A
Application number: US562815A
Authority: US
Inventors: Chase Jesse De Forest
Original assignee: Individual
Current assignee: Individual
Priority date: 1944-11-10
Filing date: 1944-11-10
Publication date: 1946-10-01
Anticipated expiration: 1963-10-01

Description

Oct. 1, 1946. J, DE F, CHA E 2,408,372 LADDER EXTENSION Filed Nov. 10, 1944 0T; onooo dsse fieiref 6774.96,

sion and with parts coil springs Patented Oct. 1, 1 946 ennon EXTENSION Jesse, De ForestChase, Kansas City Mo.

* Application November 10, 1944, Serial No. 562,815

2 Claims. 1

The present invention relates to new and useful improvements in attachment for ladders and more particularly to an extension adapted to be attached to the lower end of one of the side rails of the ladder to increase the length thereof whereby to permit the ladder to stand level on uneven surfaces.

An important object of the present invention is to provide a ladder extension of this character which may be easily and quickly attached in position to either rail of the ladder and which at the same time is strong and durable, relatively inexpensive to manufacture and otherwise well adapted for the purposes for which the same is intended.

Other objects and advantages reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawing forming part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is a fragmentary front elevational view of a ladder showing the extension in position thereon.

Figure 2 is a transverse sectional view taken substantially on a line 2-2 of Figure 3, and

Figure 3 is a side elevational view of the extenbroken away and shown in section.

Referring now to the drawing in detail wherein for the purpose of illustration I have disclosed a preferred embodiment of the invention, the numeral 5 designates the pair of side rails of the ladder and with the ladder rungs indicated at 6.

The extension comprises a short piece of material 1 of a cross-sectional area substantially equal to that of one of the rails 5 and preferably made of wood and adapted for placing in facing contact with the outer surface of one of the rails as shown to advantage in Figure 1 of the drawing.

To one edge of the member 1 is attached a pair of U-shaped plates 8 adapted to receive both the rail 5 and the member 1 within the legs 9 of the plate, the plate being free of the rail 5 and formed at its inner surface with serrations or teeth Ill adapted to bite into the edge of the rail.

The oppositeedge of the member I is formed with vertically spaced recesses ll within which l2 are positioned and through which pins l3 extend with their inner'ends embedded in the member 1 and their outer ends formed with heads l4 spaced outwardly from the adjacent edge of the extension member 1.

A clamping plate [5 extends longitudinally alongthe edge of the member I and covers the recesses H, the plate being slidably mounted on the pins [3 and retained in position thereon by the heads M of the pins.

The plate I5 is formed with a pair of lateral extensions l5 extending transversely of the adjacent edge of the rail 5 and formed at their ends with angular flanges l1 adapted to engage the side edge of the rail 5. The inner surface of the extensions l6 are also formed with serrations or teeth It adapted to bite into the edge of the rail.

A U-shaped plate H! has its leg portion recessed in the opposite side of the member I flush with the surfaces thereof with the ends of the plate I9 projecting outwardly beyond the plate l5 and provided with a pin 20 on which a lever 2| is pivotally mounted, the lever having a cam head 22 at its pivoted end adapted to bear against the plate l5 to force the same inwardly against the I member I and with the extension IS in clamping engagement with the rail 5 as shown in Figure 3 of the drawing.

The lower end of the member 1 is formed with a plurality of transversely extending openings 23 adapted to receive a pin 24 for underlying the rail 5 to further support the lower end of the rail 5 on the extension I. The opening 23 are preferably arranged in vertical rows as shown in Figure 3 of the drawing with the openings of one row staggered with respect to the openings of the other row, the pin 24 being selectively positioned in the openings of either row in order that a relatively fine adjustment of the member 1 relative to the rail 5 may be obtained.

In the operation of the device when the lever 2| is moved into its lowermost position, the

clamping plate l5 and extensions it will be projectedoutwardly from the member I by the spring l2 whereby the extension member 1 may be adjusted longitudinally of the rail 5 and the pin 24 is then inserted into one of the openings 23 to retain, the ladder in its adjusted position. The lever 2| is then raised upwardly so as to cause the cam 22 to engage theplate l5 and force the same inwardly against the member 1 thereby forcing the extensions 16 inwardly against the rail 5, the plates 8 and the extensions 3 thus cooperating to'clamp the extension member I to the opposite edges of the rail 5. I

It is believed that the details of construction, operation and advantages of the device will be readily understood from the foregoing without 7 further detailed explanation.

Having thus described the invention, what I claim is:

1. A ladder extension comprising an elongated member adapted for placing against one side of a ladder rail, a pair of stationary U-shaped clamping plates secured in vertically spaced relation to said member and adapted to receive an edge of both the ladder rail and said member for relative sliding movement and to secure the member against lateral movement from the rail as well as against forward or rearward tilting movement on the rail,v a movable clamping plate carried by the member; cam means engaging: said movable plate and adapted for moving the movable clamping plate into clamping engagement with an opposite edge of the ladder rail, and spring means yieldably urging the movable clamping plate out of clamping engagement.

2. A ladder extension comprising an elongatedmember adapted for placing: against oneside or a ladder rail, a pair of stationary U-shaped clamping plates secured in vertically spaced relation to said member and adapted to receive an edge of both the ladder rail and said member for relative sliding movement and to secure the member against lateral movement from the rail as well as against forward or rearward tiltin movement on the rail, a pair of pins projecting from a relative opposite edge of the member, a movable clamping plate slidably' mounted en the pins, cam means carried by the elongated member and adapted for moving the movable clamping plate into clamping engagement with an adjacent edge of. the: ladder rail, and spring means yieldably urging the movable clamping plate out of clamp-- i ng engagement.

- JESSE DE FOREST CHASE.