US1331953A - Stepladder with automatic spreading and bracing means - Google Patents

Description

C. 1. BROWN.

STEPLADDER WHH KUTOMATIC SPBEADWG AND BRAG'NG MEANS. APPLlCATlON FILED IAN. 21. ww,

Patented Feb. 24, 1920.

UNITED STATES PATENT OFFICE.

CHARLES J. BROVJN, OF RIVER FALLS, WISCONSIN, ASSIGNOR TO BROWN SAFETY LADDER COMPANY, OF RIVER FALLS, WISCONSIN, A CORPORATION.

STEPLADDER WITH AUTGMATIC SPREADING AND BRACING MEAN S.

Application filed January 21, 1919.

To all whom it may concern:

Be it known that I, Crmnnus J. BuowN. a citizen of the United States. residing at River Falls, in the county of St. Croix and State of Wiseonsin. have invented a new and useful Stepladder with Automatic Spreading and Bracing Means, of which the following is a specification.

This invention relates to improvements in step-ladders. and the main object is to provide a step-ladder with meanswhich will automatically spread the rear legs of the ladder in a lateral direction as soon as they are spread rearwardly from the body, rails of the ladder. and will likewise gather the legs inward to a parallel position with the rails when the front and rear parts of the ladder are brought together in the usual manner of a folding step-ladder. A second object is to so construct a step-ladder that if any of its rails, rungs or other parts get damaged they may readily be removed and substituted by new ones. A third object is to provide a step-ladder with means for taking up the lost motion or wiggling usually appearing in the upper joint of a step ladder after it has been used for some time. and which gives an unpleasant and unsafe character to the ladder.

These and a few other obiects. which will presently be descr bed and pointed out in the claims. are attained by the novel construction and combination of parts illustra ed in the accompanying drawing. in which Fioure 1 is a perspective rear elevat on of the improved stepdadder. Fig. 2 is a side elevation of the ladder with certain brace chains added. F 3 is a rear e evat on of the ladder in folded position. Fig. 4 is an enlarged portion of one of the rails and one end of a rung or step. showinng clearly how these parts are detachablv secured together. Ficr. 5 is a top View of the step shown in Fig. 4. Fig. 6 is a riqht hand nd view of the step 1-1 in its normal pos tion. as in Fig. 4. and the nut 19 in dotted line. F1027 is a detail top view of tho joint shown in the lower part of Fin. 1. Fig. 8 is a section on the line 88 in Fig. 7. Fin. 9 is an enlarged sectional view on the line 9-9 in Fig. 3. Fin. 10 is an en argement of the portion encircled by the dotted line 10" in Fig. 3. with the leg 31 omitted.

Referring to the drawing by reference Specification of Letters Patent.

Patented Feb. 24, 1920.

Serial No. 272,898.

numerals, 1O designates the side rails of the ladder; they are secured with their upper ends in resilient metallic sockets 11, by rivets, or screws, 12, and upon said sockets is secured the top step or cap 13 of the ladder. The rails are further secured together. preferably in parallel position. by a series of rungs or steps, 14, each of which is made of angle-iron turned with one flange near enough into horizontal position to constitute a step, and has each end cut loose as at 15 in Figs. 5 and 6. and bent downwardly at right angles. to form a lug 16; said lug is perforated for a screw 17. which is passed through a washer 18 and the rail 10 and provided with a nut 19. which, being placed in the angle of the angle-iron. is prevented from rotation by the flanqes thereof. The other flange stands practically in vertical position and has its proiecting end portions 20 sharpened and inserted such a d stance into the rails as will fully prevent turning movement of the step. 21 shows a broad wooden step which may be inserted wherever so desired. as a Shelf for tools. paintpots and the like. or as a more comfortab e step to stand on in the upper part of the ladder. Such extra step or s e s may have their ends detachablv inse ted as at 29 in Fig. 1 so as to be removable in case of repair; they are still firmlv he d in p ace by the rails as the latter are drawn tightly against them by the screws 17.

Fitted between the was ers 23 at the inward sides of t e sockets is a tube 24. throuc'h which and the sockets and washers 23 and 25 cxtcnrls a rod 26. having at one end a head 27 and at the other end threads 28. so as to receive a nut 29 having a handle 30. Pivoted upon said rod. with n the sockets 11. are the upper ends of the props or rear legs 31 of the ladder: s id upper ends are bev led at the inward sides. as shown at 32 in Fins. 1 and 3. so as to allow the lower ends of the legs to spread laterally when so reouired.

I employ several means. individuallv or in combination. as may be desired. for closing, spreadin and holding spread the legs of the ladder. The main device for said purpose comprises a horizontal brace 33. composed of two sections. each of which has the outer end pivoted at 34 to one of the legs, while the inner ends are overlapped and pivoted together by a bolt 35, to form an upwardly foldable knee-joint; one of the sections having a lateral lug 36 normally resting in a notch 37 of the other section. On the bolt 35 is secured a bifurcated bracket 37 in which is pivoted at 38 the junction of a V- shaped brace 39, whose front ends are socured by the pivots 40 to the rails 10. The pivots 34 and 40 are placed in such positions that when the legs 31 are closed against the rails 10, as in Figs. 3 and 9, the braces and 39 will fold upwardly as in Fig. 3 and be located between the wooden parts of the ladder, that is, will not project forwardly or rearwardly beyond the same. In this position the legs are held against accidental unfolding by turning of the nut 29, which causes the metal sockets 11 to pinch the legs. Turning of the nut is also employed to take up wear of the legs in the sockets, so as to maintain proper steadiness to the joints.

In closing up the ladder it is only necessary to give the joint of the brace 33 a slight upward push and then close the legs against the rails, the lateral closing of the legs is taken care of automatically by the braces 3933. And in spreading the ladder again for use it is only necessary to push or pull the legs rearwardly; the lateral spreading is caused automatically by the said braces, and after the braces 33 have dropped to horizontal position it is evident that no pressure, laterally, forwardly or rearwardly can cause the legs to fold.

The secondary means used consists of two braces 41, pivoted with their lower ends at 42 to the legs and having their upper ends loosely pivoted on a horizontal bar or rod 43, which is movable up and down between guides 44 and the rear edges of the rails. The folding of this device may also require a light upward push against the bar 48, but if so desired the braces 41 may be normally inclined sufiiciently to cause the bar 43 to glide upward when closing pressure is applied to the legs and the rails. When the ladder is being unfolded said braces 4:1 and bar 43 drop automatically to the lower position, in which they provide good resistance to accidental closing of the rear legs toward the rails; but as they do not spread or close the rear legs laterally they are most serviceable in combination with the braces 33. When the bar 43 is in raised position its reduced ends reeede into notches 43 in the rails, so as to permit the rear legs to be closed to the rails, as shown in Fig. 9.

Chains as may also be used to limit the spreading of the rear legs rearwardly from the rails; they are shown only auxiliary emergency means in case the braces should get out of order. They may also do for very small ladders as the only means for preventing too much rearward spreading of rear legs having the above described clamping means about their upper ends.

W hat I claim is 1. In a step-ladder, resilient metallic sockets supporting the uppermost step or cap of the ladder, the rails of the ladder forming front legs and lmving their upper ends secured in said sockets, and the upper ends of the rear legs of the ladder being pivotally secured in the sockets, a headed rod extending through the sockets and forming the pivots for the rear legs, a thumbnut at one end of said rod, a spacing tube upon the rod and filling between thetwo sockets, so as to resist them when the nut is applied to tighten the sockets against the rear legs.

The structure specified in claim 1, said rear legs having their upper ends beveled at the inward sides, to permit the lower ends of the said legs to be spread laterally, and means for closing and spreading said rear legs laterally and also for moving them toward and away from the body of the ladder.

3. In a step-ladder, the combination with the head piece and rails of the ladder, of two rear legs pivotally secured in the head piece with freedom to spread at the lower ends both laterally and rearwardly, an upwardly foldable knee-jointed horizontal brace pivoted with one end to each rear leg, a V-. shaped brace having its arms pivoted one to each of the rails of the ladder and its junction pivotally secured to the knee-joint part of the knee-brace.

4. The structure specified in claim 3. and a pair of auxiliary braces having their rearward ends pivoted one to each rear leg, and their forward and normally higher disposed ends pivotally connected to a horizontal bar, and means fixed on the rails for guiding said bar in an up and down movement along the rear edges of the rail.

In testimony whereof I aliix my signature.

CHARLES J. BROWN.

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