US1575689A - Stepladder - Google Patents

Description

Patented Mar. 9, i926.

UNITED STATES 1,575,689; PATENTOFFICE- f JOI-IN E. KALGREN, OF MINNEAPOLIS, MINNESOTAQASSIGNORITO J'. R. CLARK COM- PANY, OF MINNEAPOLIS, MINNESOTA, A CORPORATION MINNESOTA.

l STEIPLADDER.

'Application filed September T all w/Lom t may concern.'

Be it known that I, JOHN E. KALonnN, a citizen ot the United States, vresiding at Minneapolis, in the county of Hennepin and State ot Minnesota, have invented cer- 1 bility is obtained at comparatively small cost, and the elements of the ladder are so arranged that they may be very'quickly and easily assembled.

Generally stated, the invention consists of the novel devices and combinations of devices hereina'fter 'described and defined in the claim.

In the accompanying drawings, which illustrate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings:

Fig. 1 is a view in front elevation with some parts broken away and some parts sectioned, showing a portion of a step ladder embodying my invention;

Fig. 2 is a horizontal section on the line 2--2 of Fig. 1:

Fig. 3 is a transverse section on the line Bu of Fig. 1; and

Fig. i is a perspective showing` one of the step brackets removed from the ladder.

In the ordinary step ladder, the steps or treads 5 are usually of wood and at their ends are more or less rigidly connected to wooden ladder bars 6. My invention is directed to means for connecting the said steps and bars and it comprises step brackets preferably ot stamped sheet steelv bent to form shelves to support the steps and to interlock with the ends oi the steps and with the ladder bars. These brackets are bent to form step-supporting shelves 7, obliquely depending legs 8 and upstanding end plates 9. The end plates 9 at their ends are bent to form ears 10 that closely embrace the edges of the ladder bars 6, and at their upper edges they are overturned to form lock flanges 11 that overlap the ends or' the co-operating steps 5. The lower ends of the oblique legs 8 are 'turned 10, 1924. Serial N0. 736,906.

straight downward for engagement with the inner sides of the bars 6 and theyV are perforated at 12 --so that.. rivets or bolts y13 may be passed therethrough and through the legs 8. By the means already described, the brackets are locked to the ladderbars 6 in such a manner that they cannot swing laterally in the planes Vof said bars, and the stepsv are interlocked to said brackets so that they can neither move upward or downward nor can they tilt or oscillate.

To tie the steps, bars and brackets together, I use long rods or bolts 1.4L shown as headed at one end andv provided at their other ends with nuts 15. These rods are countersunk into grooves 16 formed in the bottoms of their steps, and at their end portions said rods are passed through perforations 17 in the bracket end plates 9, through perforations in the bars 6l and through washers 18. The t-ie rods 14tare thus brought above the shelf-forming portions 7 of the step brackets so that the steps may rest upon said shelves, but the said rods not only tie the parts together againstk lateral spreading movements, but they also assist in supporting the steps and in anchoring the upper portions of the step brackets to the bars. In view yof the interlocking of the upper portions of the brackets to the bars 6 at points in aline with the perforations through which the rods 14 are passed, the said brackets are caused to reinforce the bars 6 and strengthen the same at thepoints of perforation so that they are actually stronger ati said perforated points than at any other place. Of course the rods 14 securely hold the steps against endwise,that is forward and rearward, sliding movements on the shelves of the step brackets.

By referenceto Fig. 4t it will be noted that the step brackets are formed with horizontal channels to receive the ends of the steps and with vertical channels to receive the ladder bars 6 so that they thereby are O other suitable metal for that matter, and 0I 105 course the parts may be very quickly and accurately assembled since there is no possible way ot' getting the parts together incorf rectly.

It is highly important to note that with the construction herein described. the following important results are obtained: (a) when the tie red ll 1s 1n positron the step 5 will be locked against edgewise displacement from the supporting brackets; when the tie rod is removed, the step may be slid edgevvise from the (zo-operating brackets; and (c) even when the tie rod and step are removed, the braekets remain secured to the side bars et and properly positionedk for the application of a new step. Vith the said ar-rangement, therefor, if one step be broken, 'a new step may be replaced Without loosening up or removing` any of the other tie rods or steps, and the brackets do not lose vtheir positions while the substitution of steps is being made.

That I claim is:

In a ladder, the combination with ladder bars and steps, of metal brackets bent to form step-supporting shelves and `oblique depending legs, end plates extending upwardly from the step-supporting lshelves and interposed between 'said side bars and the adjacent ends of the cooperating` step, said end plates haring laterally bent ears that embrace the ladder bar.' and further previded with inturned upper iianges that overlap the ends of said steps, said steps having longitudinal channels in their under sides, and tie rods extended in the channels of said steps immediately above the shelf-forming portions of said brackets and passed through perforations in the end plates of said brackets and through perforations in said side bars, fastening devices other than said tie rods positively securing said brackets to said side bars, said rods serving to tie said side bars, steps and brackets together against lateral movements, said brackets having open ended seats into Which and from which the steps may slide edgewise When said tie rods 'are removed, ythe said rods, When applied, serving to positively lock the steps against edgewise displacement.

In testimony whereof I aflix my signature.

JOHN E. KALGREN.

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