US2779561A

US2779561A - Extension ladder jack

Info

Publication number: US2779561A
Application number: US411108A
Authority: US
Inventors: James H Blundeau
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-02-18
Filing date: 1954-02-18
Publication date: 1957-01-29
Anticipated expiration: 1974-01-29

Description

Jan. 29, 1957 J. H. BLUNDEAU 2,779,561

EXTENSION LADDER JACK Filed Feb. 18, 1954 Fig 3 7W 7 James H. B/undaau IN VEN TOR.

BY MME A norm ltd Stat Patnt i 2,779,561 EXTENSION LADDER JACK James Blundeau, Port Angeles, Wash. Application February 18, 1954, Serial No. 411,108

I 1 Claim. c1.z 4s 2 ss This invention relates to new and useful improvements in ladder brackets and more specifically provides an ex tension ladder jack for use in conjunction with a rung ladder.

An object of this invention is to provide an extension ladder jack for detachable support upon a rung ladder for positioning a scaffold board horizontally thereon.

Another object of the present invention is to provide an extension ladder jack which is simple in construction, easy to position and adjust on the ladder, versatile in utility,

well adapted for its purposes and relatively inexpensive to manufacture.

Yet another object of the present invention is to provide an extension ladder jack that is quickly and easily applied to or removed from a rung ladder without interfering with the structure of the ladder.

A still further object of the present invention is to provide an extension ladder jack which may be utilized at any position on a rung type ladder due to its adjustable features.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is a side elevational view showing the extension ladder jack of the present invention secured to a rung type ladder in various positions on the ladder showing the versatility of the ladder jack;

Figure 2 is a perspective view of the extension ladder jack of the present invention;

Figure 3 is a longitudinal, vertical section taken substantially along section line 3-3 of Figure 2 showing the details of construction of the ladder jack of the present invention;

Figure 4 is a detail section taken substantially along section line 4-4 of Figure 3 showing the details of the spring for retaining the telescopic members in adjusted position; and

Figure 5 is a detail section similar to Figure 4 showing a modified form of adjusting means for the telescopic members forming the extension ladder jack.

Referring now specifically to the drawings, it will be seen that the numeral generally designates the extension ladder jack of the present invention for attachment to a conventional rung type ladder 12 in various positions thereon when the ladder 12 is leaned against the wall of a building indicated by the numeral 14. It will be seen that the ladder jack 10 may be extended, and in its extended position, it may be utilized when it is desired to be positioned over a basement well, a flower bed or the like adjacent the lower edge of the building wall 14. Further, the device may be collapsed for positioning on the ladder 12 adjacent the contact point of the ladder 12 and the building wall 14. Further, the extension ladder jack 10 of the present invention is especially useful for 2,779,561 Patented Jan -29, 1.1 957 with a U-shaped bracket 22 having one leg thereof secured, to the end of the telescopic tubular member 18.

The U-shaped bracket 22 is generally elongated and has freeleg portions for positioning over the rung of a ladder 12. The remote end of the inner tubular member: 20 is provided with an eye bolt 24 having a flexible chain 26 secured thereto, and the chain 26 is provided with a hook .28 at its free end whichis, positionedover a rung, of a ladder 12 in an, obvious, manner. Furthenljitgwill .be

seen that the chain may be looped over the rung and secured to itself when in its contracted position if desirable.

Now referring specifically to Figures 3 and 4, it will be seen that the inner tubular member 20 is provided with a pair of diametrically opposed apertures 30 and the outer tubular member 18 is provided with two pairs of diametrically opposed openings 32 with one pair of the openings 32 disposed adjacent the U-shaped bracket 22 and the other pair of openings 32 disposed adjacent the open end of the tubular member 18. A U-shaped spring member 34 is positioned in the inner tubular member 20 and includes return bent end portions 36 which are positioned in the diametrically opposed openings 30. When the openings 3% are aligned with a pair of the openings 32, the natural resiliency of the U-shaped spring 34 urges the return bent portions 36 into engagement with the aligned

apertures

30 and 32, thereby securing the tubular members it} and 2%) in telescopically adjusted position. The spring member 34 is constructed of suitable resilient Wire of any well known construction, and by urging the return bent portions 36 inwardly, the

tubular members

18 and 20 may be adjusted relative to each other.

Referring specifically to Figure 5, it will be seen that a fastening bolt 38 having a wing nut 40 thereon is positioned in the aligned

apertures

30 and 32 for positively securing the

tubular members

18 and 20 in adjusted position.

The operation of the device will be readily understood. The

tubular members

18 and 20 are adjusted as desired, and the U-shaped bracket 22 positioned over a ladder rung. The chain 26 with the hook 28 is then positioned over the ladder rung above the U-shaped bracket 22 with the hook 28 engaging the rung or else looping the chain 26 around the rung and engaging the hook 28 with a link of the chain 26, in an obvious manner. With this specific structure, it will be seen that the extension ladder jack ltl is supported in a horizontal position for positioning a scaffold board 42 thereon in a horizontal position which is necessary for the safe use of the scaffold. Only a single ladder jack has been described, and it will be understood that a pair of the ladder jacks It) will be necessary in order to support a scaffold board.

From the foregoing, the construction and operation of the device will be readily understood and further explanation is believed to be unnecessary. However, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the appended claim.

What is claimed as new is as follows:

A ladder jack for supporting a horizontally disposed the outer end of the outer tubular member, said U-shaped bracket having one leg secured to and forming a closure for the outer tubular member, said U-shaped bracket opening downwardly for receiving a ladder rung thereby supporting one end of the jack, the outer end of the inner member having a flexible chain terminally attached thereto, a hook on the free end of the chain whereby the free end of the chain may be looped around a ladder rung above the U-shaped bracket and the hook engaged with a link of the chain thereby supporting the other end of the jack, said tubular members having spaced pairs of alignable apertures, a U-shaped spring disposed in said inner tubular member, said spring having legs extending longitudinally in said inner member and each terminating in an outwardly extending U-shaped projection having a rounded bight portion for extending through aligned apertures for retaining the tubular members in longitudinally adjusted position, said hook permitting adjustment in the length of the chain for disposing the tubular members in horizontal position for supporting a scaffold board thereon with the adjustment of the tubular mem bers permitting the board to be adjusted inwardly or outwardly in relation to a ladder.

References Cited in the file of this patent UNITED STATES PATENTS 791,531 Althoif June 6, 1905 1,452,182 Butrum Apr. 17, 1923 1,576,695 Weber Mar. 16, 1926 2,229,475 Redmer Jan. 21, 1941 2,488,480 Spirt Nov. 15, 1949 2,488,984 Pennington Nov. 22, 1949 2,548,380 Patham Apr. 10, 1951 2,577,286 Streeter Dec. 4, 1951 2,578,119 Yench Dec. 11, 1951 FOREIGN PATENTS 798,851 France Mar. 11, 1936