US426747A - Extension step ladder - Google Patents

Description

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E. .u d 0 .M o m Patented Apr. 29, 1890;

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J. L.`WOLF. EXTENSION STEP LADEEE.

No. 426,747. EatentedApr. 29, E890.i

ATTORNEYS UNITED- STATES PATENT OFFICE.

JOHN L. WOLF, OF NEV YORK, N. Y.

EXTENSION STEP-LADDER.

SPECIFICATION forming part of Letters Patent No. 426,747, dated April 29, 1890.

Application tiled February 6, 1890. Serial No. 339,484. (No model.)

To @ZZ whom it may concern:

Be it known that I, JOHN L. VOLF, of New York city, in the county and State of New York, have invented a new and useful EX- tension Step-Ladder, of which the following is a full, clear-7 and exact description.

My invention relates to an improved extension step-ladder, and has for its object to construct a simple, strong, and ldurable ladder in. two or more sections, the .extension sections of which are capable of closing upon the main or upper section to form a ladder of moderate length, or of sliding Y out from the main section together or singly to increase the height of the ladder.

A further object of the invention is to provide means for effectively bracing the sections when opened out, and of securing the braces when two sections or the main section only is used.

The invention consists in the novel constru ction and combination of the several parts, as will be hereinafter fully set forth, and pointed out in the claims.

Referenceis to be had to the accompanying drawings, forming apart of this specification, in which similar letters and figures of reference indicate corresponding parts in all the views.

Figure 1 is a side elevation of the ladder, the sections being closed one upon the other, a portion of the step-sections being broken away. Fig. 2 is a rear elevation of the ladder when in the shape illustrated in Fig. 1. Fig. 3 is a transverse section on line v3 3 of Fig. 1. Fig. 4 is a central vertical section through the ladder when at its greatest height. Fig. 5 is a transverse section on line 5 5 of Fig. 4. Fig. 6 is a similar section on line 6 6 ofFig. 4. Fig. 7 is a transverse section on line 7 7 of Fig. 4, and Fig. 8 is a detail view of a portion of a brace-bar.

. The ladder, as shown, is constructed in three sections A, B, and C; but a greater or a less number of sections may be empl'oyed,'if desii-ed.

rl'he section A consists of a top board or plate 10, forward side rails 11, rigidly secured to the under side of the top board attheir upper ends and connected by a series of run gs or steps 12 and rear legs 13, united by suit-y able cross-bars, which legs are hinged or pivoted to the under face of the top board in any. i

side, forming a slideway'l4, and each rear y leg 13 is constructed of a series of sections a, a,and a2, the sections of the legs being made to correspond inV number with the step-sections of the ladder.

The leg-sections a, c', and a? lie normally in contact with each other, the sections o. and a2 having a position parallel with each other and the main section a outside of the latter. n The bottoms of the leg-sections a are pivoted to the bottom of the main legsections a, and the upper ends of the legsec tions a2 are pivotally attached to the corresponding portion of the sections a', andy all three sections are rigidly held in their normal position by a lock-latch 15, pivoted upon the main sections a at the top and bottom, the said latches being carried transversely across the other sections to a contact with angular keepers 16, one of which is secured in horizontal alignment to each section a and a2 near the top and one to the outer section a2near the bottom, as shown in Fig. 2. One set of legs is also provided with two bracerods, one of which brace-rods 17 is pivoted or hinged to the outer section a2 at or near its bottom upon the rear face. The said rod normally extends upward and is held in contact with the section by having its upperend bent to hook shape and carried to an `engagement with a pin 18, as shown in Fig .f,y.2..I The other brace-rod 19 is hinged or pivotedat or near its upper end to the center section a', and is held normally to place by engagement with a pin near the bottom of said section in similar manner to the brace-rod 17, as is illustrated in dotted lines, Fig. 2. l

Jointed brace-rods comprising two sections 2O and 21 pivotally connectthe lower ends of the main leg-sections a with the side rails of the main step-section A, the section 21 of the brace-rod being U-shaped in cross section and the section 2O a bar capable of passing between the members of the U-section when the latter is folded up.

The step-section A has its side rails pro- TOO vided with an angular rabbet or channel la, and the second step-section B has its side rails also provided with an angular channel 14, and the said step-section B is adapted to slide in the channel of the main section A, being guided in its vertical movement by angle guide-plates 22, one of which is secured to each side near the top, and one member of said guide-plates is bent to contact with and slide upon the rear face of the rails of the main step-section A, and when the second section B is drawn down to lengthen the ladder it is prevented from leaving the main section by the angle-plates contacting with pins 23 upon the latter, as shown in Fig. 4.

Vhen the step-section B has been carried to the farthest downward point, it is held firmly to place by lock-latch es 24, pivoted upon the lower step of the main section, which latches are carried over the top step of the second section B beneath pins 25, secured in the inner face of its side rails, as illustrated in Fig. 5. The second step-section B is also provided near the top and bottom of each side rail with an upwardly-extending angleplate 2G, to constitute guides for the third step-section C 5 and in order to connect the rear leg-sections a and ai with the second step-section B, the former being folded down when the step-section is lowered, brace-bars 27 are employed, comprising two members Z) and b. The members b are U-shaped in cross-section and pivoted to the lower ends of the side rails, the members b', which are in the form of a bar, being pivoted to the members band provided at their opposite ends with a hook adapted to engage with pins upon the legs, as shown in Fig. 4. XVhen these brace-bars 27 are not needed, one member is folded in the other and both members againstthe side rail, to which they are pivotechbeing held to place byan angle-keeper 28, as shown in Fig. l.

The third step-section C is provided with straight side rails, which slide Ain the angular channels of the intermediate or second section B beneath the guide-plates 2G. This section C may, if desired, be entirely removed from the other sections, as there are no stops interposed to prevent its detachment.

The step-section C is provided with bracebars 27, constructed in like manner with the brace-bars of the second section, and when the members of the brace-bars are folded up they are held to place by a latch-bar 29, one of said bars being pivoted to the upper step near each side rail and made to terminate in loops 30, which loops are passed over the upper or pivotally-connected ends of the bracebar members, as shown in Fig. 2.

To lengthen the ladder as much as possible, the second step-section B is drawn down upon the main step-section until the guide-plate 22 contacts with the pins 23, and the lower section C is thereupon drawn downward, and the latch-bars 31, which are pivoted beneath the lower step of the intermediate section, are carried beneath the upper step of the lower section to an engagement with supportingpins 32. Thus each step-section is held in its place. The leg-sections are then folded down one from the other and carried out to the position illustrated in Fig. 4, whereupon the lower lock-latch l5 upon the main leg-section is carried over and made to contact with the anglekeepers upon the second lesection a', and a similar latch-bar l5, which is attached to the lower end of the intermediate leg-section ct', is carried over and made to contact with the angle-keeper 16 upon the upper end of the third leg-section a2. The brace-bars are thereupon folded out and made to engage with pins upon the leg-sections, and the brace- bars 17 and 19 are folded over at the rear of the leg-sections transversely of the same, one at the bottom and the other at the joint above, and the hooked extremities of the said bracebars are made to en ter pins in the leg-sections opposite to those to which they are pivoted.

Having thus described my invention, I claim as new and desire to secure by Letters Patentl. In an extension step-ladder, the combination, with a main step-section having a longitudinal channel produced in its side rails,I

a second step-section provided with guideplates and capable of sliding in the channels of the main section, and legs hinged to the main step-section, of auxiliary leg-sections pivoted to the lower ends of the main leg-sections and capable of folding upon said main leg-sections, and brace-bars pivoted at the lower ends of the second step-section, the said bars comprising two members, one U-shaped in cross-section and the other in bar form, adapted to close in the U member and contact with the sides of the step-section, substantially as shown and described.

2. In an extension step-ladder, the combination, with a main step-section having a longitudinal channel produced in its side rails, an intermediate step-section held to slide in the channels of the main step-section, and also provided with channels in its side rails, guide-plates secured to the side rails of the intermediate step-section, proj ecting forward and rearward therefrom, and a third stepsection capable of sliding upon the intermediate step-section, of leg-sections pivoted to the main step-section, and two pivotally-connected auxiliary leg-sections pivoted to the lower end of each of the main leg-sections, and means,'substantially as shown and described, for locking the leg-sections to place when folded and unfolded, as and for the purpose specified.

In an.extenson-ladder, the combination, with a main step-section. having a longitudinal channel produced in its side rails, an intermediate step-section held to slide in the channels of the main step-section, and also provided with channels in its side rails, guideplates secured to the side rails of the intermediate step-section, projecting forward and rearward therefrom, and a third step-section TIO main leg-sections, brace-bars pivoted to thel side rails of the intermediateand outer stepseotions, each brace-bar comprising two pivotallyconnected members, one being U- shaped in cross-section and the other rect- 1o angular, and look-latches pivote-d to several of the leg-sections, adapted to contact with keepers secured upon others of the 1eg-seotions, Whereb'y said sections are held rigidly in a folded or an unfolded position, substantially as described, and for the purpose speoi- 15 fied.

JOHN L. WOLF. Witnesses:

S. HELLER, L. C. RHEIN.

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