US700028A - Step-ladder. - Google Patents

Description

H. L. FRIZELL.

-'STE P LADD (Application filed Mar. 02.)

(No Model.)

' Patented ma I3, 1902,

W! up UNITED STATES PATE T QFFIGE.

HERBERT L. FRIZELL, or BOSTON,MASSACHUSETTS.

, V STEP-LADDER.

SEECIELGATIQN forming part of Letters Patent No. 700,028, dated May 13, 1902. Application filed March 15, 1902. Serial No. 98,365. (No man.)

To all whom it may concern:

Be it known that I, HERBERT L. vFRIZELL, a citizen of the United States, residing in the city of Boston, in the county of Suffolk'and State of Massachusetts, have invented a new and useful Improvement in Step-Ladders, of which the following is a specification.

My invention relates to an improvement in step-ladders respecting'the manner of constructing and uniting the side-rails and steps thereof and securing the same adj ustably' together; and .the object of my improvement isto secure great strength and rigidity in the joints and a steady support and firmness in the ladder, with ready adaptation for dis connection at the joints or knocking down for compact and ecomom'ical shipment and storage of the same. I attain this object in the manner and by the means illustrated in the accompanying drawings, in which Figure 1 is a perspective view of knockdown step-ladder embodying my invention. Fig. 2 is an enlarged side elevation of portions of a side rail and a step united and secured in accordance'with myinvention, andFig. 3-

is a horizontal section of the same.

Referring tothedrawings, Ain Fig. 1 represents the ladder complete in its open and self-supporting position. B B represent its two inclined side rails, to which the horizon? tal steps 0 C are secured by the means and in the manner which will be described and to which my invention is confined.

The ends of the upholding-steps enter full size into grooves cut in theinner faces of the rails at proper intervals and but partly through the same, as shown clearly in Fig. 3. Thus the strength of the wooden parts is but slightly impaired at their junction and the ends of the steps have a fair and firm bearing against the inner faces of the grooves. Each step near its ends and midway of its width has holes bored throughit, into which: are inserted from the under sidetwo eyebolts D, the eyes of which are threaded and project from the under face of the step, while the upper ends of the bolts pass through washers sunk into the step, and are riveted downflush withthe'upper face or tread of the step. Through the side rails just belowthe inserted ends of-the steps and parallel therewith are extended a corresponding numand the inner ends of which are threaded into the eyes of bolts D, while their outer heads E sink into washers B, which bear against the outer fa'cesof the rails. When all the parts arethus j oined'together, as shown in Fig. 3, the screws E are threaded into the eyes ofbolts D, and by properly turning the screws the steps are drawn firmly to their end hearings in the grooves, and so rigidly secured thereby as to prevent movement of the parts separately at their joints and all lateral swaying and unsteadiness of the ladder from looseness of joints.

Various well-known methods of constructing ladders and securing the side rails and steps together bymeans of mortises and mortises and tenons have been adopted, all of which were unlike mine and have been weaker in the joints and without adaptability'for knocking down or adjusting. My method and means of uniting the rails and steps and binding them togethermuch more strongly,

reinforcesand braces the joints and makes ,the unionrof the parts simply and conveniently adjustable to take up wear and looseness and adaptable totemporary separation for packing and transportation. The ladder is of usual construction in the matter of its hinged supporting legs or posts and upper platform, my present invention being confined to the means and method of uniting the steps and rails, as beforedescribed.

I claim V 1. A knockdown step-ladder comprising two side rails, joined together at proper in tervals by a series of horizontal upholdingsteps,the ends of which are insertedin grooves in the rails, and secured and reinforced by 'ofiset binding-screws passed up to their heads through the rails below and parallel with the under-sides of the steps, and threaded into the eyes of-bolts inserted 'in and projecting from-the steps, and by which means the rails and steps are detachably drawn together and their joints braced and reinforced, substantially as specified.

2. The combination of upwardly-inclining side rails B, B, having groovesorrecesses in their innerfaces;-steps'O,-O, having their ends. inserted in the'recesses and-bearing against the interior of the same; eyebolts D,

her of binding-screws E offset from the steps riveted in holes near the ends of the steps with their threaded eyes projecting from the under sides thereof; and binding-screws E extended through the rails parallel with the under sides of the steps, and oifset therefrom to enter the threaded eyebolts, while their heads E press against the outer faces of the rails, through interposed washers 13,

whereby the separable joints of the united rails and steps are strongly reinforced and 1o braced; substantially as specified.

HERBERT L. FRIZELL.

Witnesses:

JAMES F. DE CASTRO, EUGENE HUMPHREY.

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