US2594070A - Ladder - Google Patents

Description

G. E. REAGLE April 22, 1952 LADDER Filed March 2 f1951 Patentecl Apr. 22, 1952 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to improvements in ladders and particularly to extension type ladders and to rail structure that includes special means for supporting the rungs.

Additionally, the invention relates to improve-4 ments over my Patent #1,96l,781, granted Ju'ne 5, 1934. This patent related particularly to structure by which to provide additional support for the rungs of previously constructed ladders, and also to provide support for rungs that had become weakened through wear or strain in use.I

Ladders of the rung type, as distinguished from those having steps, become unsafe after being in ladder, and also the most dangerous to a user;H

is the place of interfitting of rungs with side rails. In all instances, the rung ends project into openings in the side rails. These ends are not exposed to view and, therefore, it is difficult to determine, until an actual break occurs, whether or not the rung end is sufiiciently sound 'and of such condition as to support the weight of a user.

It is a purpose and object of the present invention to provide a construction for rung type ladders that will adequately serve its purpose almost without regard for loads imposed on the rungs.

It is a purpose and object 'of this invention to provide a rung type ladder having reinforcing means to increase the strength and durability of the rails and rung ends.

It is also an important object of the invention to provide a ladder that, although including the usual wood rails and rungs, is reinforced against bowing through the use of appropriately located metal reinforcing strips.

Another and important object of the invention lies in the provision of ladder rung supports that eliminate the previous requirement of nailing the rungs directly to the ladder rails. In this connection, it is pointed out that the Weakest point in all conventional ladder rails is at the aperture for the rung and the place of nailing.

Other objects and advantages of the invention will be more fully understood from a consideration of the following speciflcation, taken in conjunction with the accompanying drawing; and in t which Fig. l is a perspective view of a portion of a ladder in which one form of the invention is embodied;

Fig. 2 is an enlarged vertical sectional view, taken substantially on the line 2-2 of Fig. 1;

Fig. 3 is an enlarged vertical sectional view, taken substantially on the line 3-3 of Fig. 2; and

Fig. 4 is a fragmentary perspective view of one rail strap and one of the rung supports formed from said Strap.

Referring more particularly to the dra-Wing, the reference numeral lll is employed to generally designats a ladder embodying one form of the present invention. This ladder may be of any suitable length and comprises a pair of rails Il and a plurality of rungs l2. of each rail is formed with a wide, shallow recess M. Furthermore, each rail is drilled to provide the required number of rung receiving openings l6, the spacing of such openings being preferably uniform throughout the length of the ladder, but subject to different dimensional span, depending on the particular type of ladder. As is customary, the openings I 6 do not extend completely4 through the rail, not only for the purpose of improving the rail appearance but also to give added strength thereto by the continuing portion l'I.

It is proposed to provide a metal strip [8 for each rail. Each strip l8 is formed of fairly heavy gage material and is of a width to fit snugly in the grooves lll of the rail. These strips preferably extend the full rail length, although it is contemplated that they may terminate short of the rail ends, provided they stop above and below the top and bottommost rungs of the ladder. A plurality of rung supports I 9, in the form of saddles, extend inwardly from one face of the strip. Although these supports may be in the form of separate brackets, Welded or otherwise joined to the strip |8, it is found preferable and less costly to form the supports directly from the strip itself. In Fig. 4 of the drawing it is clearly shown that the body 2! of each support, prior to its being Shaped into saddle form, is of the proportions of the opening 22 in the strip. In order that the support IQ may have adequate rigidity in its horizontally bent position, the central, inner part of the curved portion and adjacent part of the strip are formed with connected ribs 23 and 24. Although these ribs are not of considerable proportions, they obviously, as can be seen in Fig. 3 of the drawing, serve to adequately The inner face 13 formed with an upwardly offset prong 21.

rigidify or brace the rung support. The rear marginal edges 26 of each of the supports is These prongs are also formed from the stock of the strip, as is clearly indicated by the pointed slots 28 which are continuations of the opening 22 from which the support I9 is formed. The offset of the prongs 21 is for the purpose of permitting their entering and resting against the opening l6 of the rail ll.

In the present illustration of a ladder, it will be noted that rungs 29 include ends 3| of lesser diameter. These ends are intended to press wfit the openings |6 and do so by reason of the crowding effected by the prongs 21.

To assemble a ladder embodying the present invention it is of course necessary to kprovide the shallow recesses 14 in the rails. Strips I'8, previously'cut to desired length and stamped to provide rung supports, as already brought out, are

.nextiplaced in the grooves M. Each strip is flush with the inner face of the rail towhich it is applied and is anchored to said rails with screws or nails 3-2. It has been found convenient to locate four such screws directly beneath each rung support and two directly above, but it will of course be understood that the number and position of these screws may be changed as required. After the strips 18 have been mounted and Secured to the rails, corresponding ends 3| of rungs v29 are projected through the openings 22 of :the strip and forced into the rail openings |6. As already mentioned, the rail ends have a snug .fit due to crowding of the prongs 21, this crowding being such that the lprongs are actually .more or 1ess pressed into the under surface of the rung ends. At the place of meeting of the ends 31 with the larger diametered portion of the rung, there is of course a shoulder 33. The lower part of this shoulder rests against the offset flanges 34 of the Iprongs 21. After the proper number of rungs 29 have been engaged With one of the rails, two screws or nails 36 are projected through openings 31 in the supports |9 into engagement with the rungs. Following securing all of the rungs to the supports carried by one rail, the other ends 3| of the rungs are projected into the Vopenings in the other rail and Secured in the manner above described.

It will .be observed that the present invention not only provides a metal reinforcement for each wooden rail, but also Vin part relieves the rails from full support of the rung ends through the extending metal supports [9. Furthermore, it Will be noted that no toe-nailing is required to anchor the rung ends to the rails. The entire anchoring of the rungs is accomplished through V'the use of screws or nails 32 and 36 that at distant points engage rail and rung. The invention also finds advantage through the combiprovided in the present invention so materially prevent such bowing as to enable the use of lighter weight or smaller stock for rails. Through the use of lighter weight rails it is not only possible to absorb the cost of the additional metal strips, thus rendering a ladder constructed in accordance with the invention no more expensive than a conventional ladder, but it is also pointed out that ladders of this type are, at best, unwieldy and difficult to maneuver, and through the-use of lighter weight'rails, and possbly light weight metal strips, the ladder of the invention may be easily maneuvered from one position of use to another.

Although applicant has shown and described only one Vmodifieation of the invention, it will be apparent that Variations in the structure thereof may be made without departing from the spirit and scope of the invention as set out in the annexed claims.

.Having thus set forth my invention, what I claim as 4new and .for which I desire protection by Letters y.Patent is:

1. A rung type ladder comprising a pair of Wooden side rails, metal reinforcing strips for said rails, each of Vsaid strips being mounted in a recess on the inner side of each rail and secured in a position flush therewith, a plurality of saddle-like rung supports Vformed integral with and extending at .right angles to the direction of the length of each strip, each of said supports registering with a rung-end opening in said rail,

a rung end mounted on each support and ex-V extending Vat .right angles to the direction of the length of each strip, eachof said supports being substantially-coincident with the bottom of the openings .in said rails, a rung end mounted on each support and extending into the corresponding side rail opening, integral means serving to rigidify said supports-With said strips, and prongsintegral with said supports projecting into theubottomrof said openings and serving to wedgesecure the rung ends.

- GEORGE E. REAGLE.

REFEa'ENoi-:s oIfrED T-he following references are 'of record in vthe file of this patent:

UNITED STATES PATENTS Number Name Date 305,582 Finnegan Sept. 23, .1884 488,428 Frye et al. --.D Dec. 20, 1892 897,157 Rowe Aug. 25, 1908 1,961,781 Reagle June 5, 1934

Images