US2171863A - Ladder - Google Patents

Description

' 1P. PlRscH Sept. 5, 1939.

LADDER Filed May 17, 1937 kill lllllllll,

ATroRNEY.

Patented Sept. 5, 1939 UNITED STATES LADDER.

Peter Pirsch, Kenosha, Wis., assigner to Peter Pirsch and Sons Co., Kenosha, Wis., a firm composed of Peter Pinch, W. B.

Pirsch Even Pinch, Cella Application Mn; 1-7, 1931, serial No. 143,024

3Claims.

This invention relates to improvements in ladders.

In the manufacture of ladders, the securing of the ends of the rungs in position has heretofore presented a problem. AThese rungs must be rigidly connected to the side rails in order to properly brace the ladder structure and also to hold the rungs themselves against loosening and turning movement. Ladders as constructed today may be formed in a variety of Ways: rungs of aluminum or other metal may be used in conjunction with side rails of wood; the ladder may utilize metal for both the side rails and the rungs; or the ladder may be of a standard type employing wood for both the side rails and rungs. Where metal rungs are employed, the problem of securing the ends of the rungs in position is increasingly diflcult, and welding has heretofore been resorted to to make a firm connection.

It is one of the objects of the present invention to provide a simple means for anchoring the ends of the rungs in position and for spacing and strengthening the elongated members forming the side rails, which means is adapted for use in connection with any of the above types of ladder constructions, and which means is particularly well adapted for use in connection with metal rungs.

It is a more specic object of this invention to provide an improved ladder construction comprising side rails each formed of a pair of spaced elongated members, rungs positionable between the side rails, and means forming spacers or truss blocks positionable between the elongated members forming the side rails and specially constructed to receive and firmly anchor the ends of the rungs.

A further object of the invention is to provide a ladder construction as above described whereform presenting relatively long bearing sleeves for the ends of the rungs, which sleeves may be broached to proper form to snugly receive the ends of grooved metal rungs or the ends of wooden rungs where these are employed.

Other objects of the invention are to provide a ladder construction embodying a spacer block wherein the latter is of open form to permit riveting through exposed exterior portions of the bearing sleeve and also to provide openings for reception of the hand when the ladder is being used; to provide a ladder construction adapted for use in connection with either a lap type of extension ladder or a lapless type; to provide a 55 ladder which permits the use of aluminum in the spacer blocks are of' metal and of spiderv (ci. zzaqss) throughout, if desired, thereby providing a construction of minimum weight; to provide a ladder in which both the side rails and rungs are reinforced and strengthened by the improved spacer and truss blocks; to provide a construction which eliminates the necessity of welding the ends of metal rungs in position when metal is used for the rungs; and to provide a construction which is relatively simple and inexpensive to manufacture.

With the above and other objects in view, the invention consists of the improved ladder and all its parts and combinations as set forth in the claims and all equivalents thereof.

In the accompanying drawing in which the same reference numerals designate the same parts in all of the views:

Fig. 1 is a perspective view of a fragment of a ladder;

Fig. 2 is an enlarged fragmentary view looking at the inner side of a side rail assembly, the rung being shown in section, and other parts being broken away and shownin section;

Fig. 3 is a perspective view of oneof the spacer members alone;

Fig. 4 is a fragmentary perspective view showing a modified construction wherein the side rails are formed of spaced channel members of aluminum or other metal;

Fig. 5 is a sectional view through one ofthe rungs of -the modification looking at the side rail and spacer assembly; and

Fig. 6 is a sectional view taken/ o'n line 6--6 of Fig. 5.

Referring more particularly to Figs. 1, 2 and 3 of the drawing, the ladder shown therein comprises spaced side rail assemblies 8 and 9, each comprising a pair of elongated members I and III. Secured at intervals between the elongated members I0 and III are the improved spacer members designated generally by the numeral I I. These spacer members are preferably formed of aluminum or other metal and are of spider form. In the preferred embodiment each spacer includes a strip of metal I2 which is secured to the elongated member I Il by bolts I3, said strip having a sleeve portion I4 projecting therefrom as shown. Extending angularly from the sleeve are arms I which have their outer ends flanged as at I6 whereby the arms may be secured by the bolts I'l to the elongated member L0.

In the form of invention shown in Fig. 1, the elongated members lli and I 0' are formed of wood. This is preferred in many cases because of the fact that wood is not a conductor f electricity, and there is therefore no danger when the ladder touches a live wire. Elongated mem` bers of wood are also preferred by many because of the fact that they are not as cold on the hand in the winter time. Frequently. however, where maximum lightness is desired, the elongated members comprising the side rails are formed of light weight metal such as aluminum, and the improved spacer bloei is well adapted for use in conjunction with side rail assemblies of this type. By referring to Fig. 4, it will be seen that the elongated members forming the side rails l1 and i8 are of channeled metal with the open sides of the channel facing each other. The spacer members may then be iltted between the flanges I9 and 20 of the channels as shown and ller strips may be employed if desired. Various other forms of side rails may be employed in connection with the improved spacer members, such as side rails formed of I-beams.

The use of rungs formed of aluminum or other light weight metal is highly desirable due to the fact that said rungs resist breakage and are light in weight, and the present invention lends itself well to use in connection with rungs of this type. These aluminum rungs 2| are usually formed with longitudinal ribs 22 to prevent slippage of the foot. Accordingly in securing the ends of metal rungs in position the sleeve portions il of the spacers are suitably breached to provide grooves 23 for cooperation with the ribs of the rungs. The ends of the rungs are then inserted into the sleeves I4 with a driving fit, and they are thus tightly secured in position. The sleeves, it is to be noted, are suiliciently long to provide a relatively long bearing surface for the ends of the rungs. In addition the cooperating ribs 22 and grooves 23 prevent turning movement of the rungs in the sleeves. In order to further secure the rungs in position and against turning movement, a rivet 24 may be inserted through an exposed exterior portion of the rung, the rung being tubular in form. Due to the fact that the spider-like form of the spacers exposes exterior portions of the sleeve I4, this riveting is a simple matter. It will therefore be seen that a very secure connection can be made with the ends of the rungs without in any way resorting to welding. 1

Where wooden rungs are employed, it is preferred to also broach the sleeves I4 to provide the grooves 23 separated by the ribs between the grooves. The ends of the wooden rungs are then driven into the sleeves with the ribs between the grooves cutting into the Wood. 'I'hus the wooden rungs may also be firmly secured in position and against turning movement. It is also possible to drive a nail or other securing means into the wooden rung in place of the rivet 2l used with the metal rung construction.

From the above it may be seen that the improved construction is well adapted for use in connection with side rails of either wood or metal or inconnection with rungs of either wood or metal. It isA further apparent that the open structure of the spacer simplifies the insertion of seeming members such as the rivet 24. The spider construction of the spacers also serves as a truss to strengthen and brace the entire lad-l der construction. In using a ladder it is undesirable to have the elongated members forming the side rails closed for any appreciable length. 'Ihe spider-like spacer blocks are therefore particularly desirable because the hand can be inserted around the elongated member Il and between the spider arms Il. In addition, the spacer blocks of the present invention are formed of metal and therefore there is no trouble in connection with shrinkage such as was heretofore encountered when wooden spacer blocks were employed. With the wooden blocks, not only the rungs became loose, but also the bolts which held the wood spacers to the side rails.

Although only a few forms of the invention have been shown and described, it is obvious that various changes and modifications may be made without departing from the1 spirit of the invention, and all of such changes are contemplated as may come within the scope of the claims.

What I claim is:

1. A ladder comprising side rails each including a pair of spaced elongated members, spacers secured at intervals between said spaced elongated members of each side rail, each spacer comprising a strip of material secured to one of said elongated members of a side rail, a bearing sleeve projecting from said strip, arms projecting angulargly from said sleeve and secured to said other elongated side rail member, and rungs having end portions received in said sleeves.

2. A ladder comprising side rails each including a pair of spaced elongated members, spacers secured at intervals between the spaced elongated members of each side rail, each spacer including a metal bearing sleeve, means for connecting said sleeve to one of the spaced members in a position relatively close to said member, and spaced arms extending at an oblique angle away from each other connecting the sleeve to the other spaced member to provide a relatively large hand opening between said arms, and rungs having end portions received in said sleeves.

3. A ladder comprising side rails each forming a pair of spaced elongated metal members having channel portions opening toward each other, spacers secured at intervals in said channel portions and connecting the elongated members together, each spacer including a metal bearing sleeve of a minimum legth substantially equal to the width of the channels, and arms connecting said sleeves to the channels, said arms being of a Width to ilt between the flanges of the channels and said width of the arms extending in the same direction as the length of the sleeve, said sleeves andspacers being substantially conned within the channels, and rungs having end portions received in said sleeves.

PETER PIRSCH.

Images