US725188A - Ladder. - Google Patents

Description

PATENTED APR. 14, 1903.

W. WILLIAMSON.

LADDER.

APPLICATION FILED 0019, 1902.

,ATTORNEY rrlen Sterne lla'rnr rrncnt IVILLIAM WVILLIAMSON, OF SAGINAW, MICHIGAN.

LADDER.

$PECIFICATION forming part of Letters Patent N 0. 725,188, dated April 14, 1903.

Application filed October 9, 1902.

To aZZ whom it may concern:

Be it known that LWILLIAM WILLIAMSON, a citizen of the United States, residingat Saginaw, in the county of Saginaw and State of Michigan, have invented certain new and useful Improvements in 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 appertains to make and use the same.

Myinvention relates to ladders that are convertible for use either as extension or step ladders.

My invention provides a joint for locking the two members of the ladder when spread to form a step-ladder and also comprises a device for guiding the extension member while it is being elevated or lowered and for keeping the members in line when extended. In connection with the joint I also provide a simple means whereby the two members may be released from each other without having to be first extended full length.

The improvements are illustrated in the accompanying drawings, in which- Figure 1 is a perspective view of a ladder having my improvements attached used as a step-ladder. Fig. 2 is an elevation of the same ladder closed. Fig. 3 is a detail showing the joint when the ladder is locked in position for use as a step-ladder or scaffold-support. Fig. 4' is a perspective view of the bracket secured to the rail of the upper member. Fig. 5 is a detail showing the top of the upper member slightly raised above the top of the lower member. Fig. 6 is a section on the line 'y y of Fig. 5. Fig. 7 is a perspective view of the plate secured to a rail of the lower member.

Similar numerals refer to similar parts throughout the several views.

The device consists of a pair of plates 1, secured to the upper ends of the rails of the lower member by screws or otherwise, and a pair brackets 2, secured by screws or otherwise to the upper ends of the upper member, each plate operating with its corresponding bracket to form one hinge member. The plate 1 has an extension 1 carrying an inwardlyextending flange 1, which guides the rail of the upper member when being extended, as shown in Fig. 5, and keeps the two members in line and prevents 1 heir sagging when used as an extension-ladder. Plate 1 has also a projecting lug 1 forming a fulcrum about which the upper member turns when the bottoms of the two members are brought together, as shown in Fig. 2, for storing the ladder or for putting it into position to slide up so as 'to form an extension-ladder. The plate 1 has also a projecting pin 1, adapted to engage a transverse slot 2 in the bracket 2. This slot extends beyond the edge of the ladder-rail 3 and terminates in a downward and forward opening 2*, adapted to receive the pin 1 of the plate 1.

To convert the extension-ladder into a stepladder, the upper-member is lowered until the pin 1 enters the opening 2 of the slot 2. The bottoms of the laddermembers are then separated and the pin goes to the end of the slot, as shown in Fig. 3. The bottom of flange 1 of the plate 1 then bears against the rear edge of the bracket 2 and locks the two members in position for use as ,astep-ladder or scaffold-support, as shown in Fig. 1.

The slotted brackets 2 on the rails of the upper member are preferably provided with smoothly-rounded ends 2 to prevent marring objects against which they rest.

I provide means for easily releasing and separating the two members of the ladder withoutextending them by mounting the pin 1 on a pivoted arm 1", so it can move back in a slot 1 of the plate 1 to a position where it will permit the bracket 2 to slide past without engaging the opening 2", as above described.

By the means above described I have produced a joint which in its most essential features consists of but twoparts -the flanged plate 1 and the bracket 2-both of which are applied without the necessity of expending time and labor in mortising or cutting and fitting the rails of the ladder. Both parts are strong and of such shape as to give small chance for the accumulation of dirt that might otherwise clog them and prevent their free action.

What I claim as my invention, and desire to secure by Letters Patent, is as follows:

1. In a combined extension and step ladder; the combination of a lower ladder member; a plate fixed to the inside of each rail of said member; a lateral extension on said plate; an inwardly-projecting flange on said extension; a pin projectinginwardly from the face of said plate; a lug on said plate projecting inwardly to form a fulcrum; a bracket secured to the upper end of each rail of the extension member; a transverse slot in said bracket; and a forward extension to said bracket forming a downwardly and forwardly extending passage to receive said pin for interlocking the ladder-sections.

2. A joint for extension and similar ladders comprising; a plate fixed to the upper end of the rail of the lower ladder member; a lateral extension on said plate; an inwardly-projecting flange on said extension; a lug on said plate projecting inwardly to form a fulcrum to guide the upper member; a pivoted arm secured to said plate; a pin carried by said arm and extending inwardly from the face of said plate; a bracket secured to the upper end of each rail of the extension member; a transverse slot in said bracket; and a forward extension to said bracket forming a downwardly and forwardly extending passage to receive said pin forinterlocking the ladder-sections.

3. A joint for extension and similarladders comprising in combination; a plate fixed to the rail of the lower ladder member; a lateral extension on said plate; a pin projecting inwardly from the face of said plate; a bracket secured to the upper end of the rail of the extension member; a transverse slot in said bracket; and a forward extension to said bracket forming a downwardly and forwardly extending passage to receive said pin for interlocking the ladder-sections.

In testimony whereof I affix my signature in presence of two witnesses.

WILLIAM WILLIAMSON.

Witnesses:

P. M. HOLDSWORTH, JAMES C. HANSON.

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