US3136387A - Ladder construction - Google Patents

Description

June 9, 1964 H. B. RICH LADDER CONSTRUCTION Filed Oct. 17, 1962 Attornevs.

United States Patent M 3,136,387 LADQER CQNTRUCTTON Howard B. Rich, (Carroiiton, K assignor to Howard B. Rich, inc, Carroiiton, Ky a corporation of Kentucky Filed Oct. 17, 3952, Ser. No. 231,154 3 Claims. (61. 182-216 This invention relates to stepladders and to steps therefor.

An object of this invention is to provide a strong stepladder of light weight having sturdy, rigid, reinforced wooden steps.

A further object of this invention is to provide a stepladder in which steps thereof are held in place in gains in side rails of the ladder by tension rods which alsore inforce and support the steps.

A further object of this invention is to provide a ladder step construction in which a block which underlies the step cooperates with the rod which underlies the step to provide a truss effect supporting the step.

A further object of this invention is to provide a stepladder structure of this type in which the step is provided with a groove underlying the step in which a tongue portion of the wedge-block is received and in which the rod holds the wedge-block in place with the tongue thereof in the groove and in which end portions of the rod extend into the groove to lock the step in place in the gains of the side rails.

The above and other objects and features of the invention will be apparent to those skilled in the art to which this invention pertains from the following detailed description, and the drawing in which:

FIG. 1 is a perspective view of a stepladder constructed in accordance with an embodiment of this invention;

FIG. 2 is an enlarged fragmentary perspective view partly broken away and in section showing portions of side rails together with one step of the stepladder;

FIG. 3 is a view in section taken on a line 33 in FIG. 1;

FIG. 4 is a fragmentary view in front elevation showing one step in association with fragmentary portions of side rails of the stepladder; and

FIG. 5 is an enlarged fragmentary view of an end portion of one of the-steps in association with a fragmentary portion of one rail of the ladder.

In the following detailed description and the drawing, like reference characters indicate like parts.

In FIG. 1 of the drawing is shown a collapsible stepladder having side rails 12 and 13 hinge connected at their upper ends to brace or stay legs 14 and 155. The upper end of the ladder is provided with the usual platform 1d. The stay legs 14 and 15 are provided with cross braces 18 and 19. The rails 12 and 13 are connected to the stay legs 14 and 15 by means of braces 20 and 21 of the usual construction. As shown, each of the braces 2i and 21 comprises links 22 and 23 pin connected as at 24 and 25 to the side rails and the stay legs as shown. The adjacent ends of the links are pin-eonnected as at 26 to form a hinge.

The ladder is provided with steps 28, the construction of each of which is shown more particularly in FIGS. 2 to 5, inclusive. Each step 28 is formed of a wooden block provided with outwardly extending projections or tongues 30 and 31' (FIG. 2). The tongues 30 and 31 extend into gains 32 in the side rails. The step extends downwardly from the tongues 3t) and 31 forming shoulders 33 which face and engage the side rails. A lengthwise groove 34 (FIG. 3) is formed in the underside of the step. The groove 34 receives a tongue 36 of a T-shaped wedge block 37. The tongue fits snugly in the groove 34 with a cross-bar portion 38 underlying and resting 3,135,387 Patented June 9, 1964 ice against a bottom face of the step. A shallow groove 39 along the center of the cross-bar portion 38 of the wedge block 37 receives a central portion of a tension rod 41.

The tension rod 41 extends through bores 42 (FIG. 5) and 43 (FIG. 2) in the side rails 13 and 12, respectively, and into end portions of the groove 34 adjacent the side rails as shown most clearly in FIGS. 2 and 5. A nut 44 threaded on the tension rod 41 engages a washer 46 and grips the washer 46 against an outer face of the side rail 13. A similar Washer 47 is engaged by a head portion d8 of the tension rod, as shown in FIG. 5. The bores 4-2 and 43 are aligned with the groove 34 of the step so that portions of the tension rod adjacent the side rails are received in the groove 34- to lock the step in position between the side rails with the tension rod forming a trussed structure with the block 37 to strengthen and support the step centrally thereof.

The ladder structure illustrated in the drawings and described above is subject to structural modification without departing from the spirit and scope of the appended claims. I

Having described my invention, whatl claim as new and desire to secure by Letters Patent is:

l. A ladder which comprises a pair of side rails, there being gains in said side rails, a step spanning the rails support the block and the step, portions of the tension rod I adjacent the side rails being received in the groove of the step to lock the step in position in the gains.

2. A ladder which comprises a pair of side rails, there being gains in said side rails, a plurality of steps spanning the rails, tongues at end portions of the steps received in the gains, shoulders on each step adjacent the tongues and engaging inner faces of the side rails, each of said steps having a lengthwise groove in the underside threeof, a T-shaped block underlying each step with a tongue portion of the block received in the groove and a cross bar portion thereof outside the groove, and a tension rod for each step linking the side rails, each tension rod having a central portion underlying the cross bar portion of the block so support the block and the step associated therewith, portions of each tension rod adjacent the side rails being received in the groove of the step associated therewith to lock the step in position in the gains.

3. A ladder which comprises a pair of side rails, there being gains in said side rails, a step spanning the rails with end portions of the step received in the gains, said step having a lengthwise groove in the underside thereof, a block underlying the step with a tongue portionof the block received in the groove and a crossbar portion thereof outside the groove, a recess in the crossbar portion of the block, and a tension rod linking the side rails, the tension rod having a central portion underlying and engaging the crossbar portion of the block and extending into said recess to support the block and step, portions of the tension rod adjacent the side rails being received in the groove of the step to lock the step into position in the gains.

References Cited in the file of this patent UNITED STATES PATENTS 1,641,591 Kalgren Sept. 6, 1927 1,954,434 Thrasher Apr. 10, 1934 FOREIGN PATENTS- 1,036,1 19 France Apr. 22, 1953 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N00 3 l3 387 June 9 1964 Howard Ba Rich It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2 line 47 for "50" read to Signed and sealed this 10th day of November 1964,

(SEAL) Arrest:

EDWARD J. BRENNER Commissioner of Patents ERNEST W. SWIDER Aimsting Gffieer

Claims (1)

1. A LADDER WHICH COMPRISES A PAIR OF SIDE RAILS, THERE BEING GAINS IN SAID SIDE RAILS, A STEP SPANNING THE RAILS WITH END PORTIONS OF THE STEP RECEIVED IN THE GAINS, SAID STEP HAVING A LENGTHWISE GROOVE IN THE UNDERSIDE THEREOF, A BLOCK UNDERLYING THE STEP WITH A TONGUE PORTION OF THE BLOCK RECEIVED IN THE GROOVE AND A CROSS BAR PORTION THEREOF OUTSIDE THE GROOVE, AND A TENSION ROD LINKING THE SIDE RAILS, THE TENSION ROD HAVING A CENTRAL PORTION UNDERLYING AND ENGAGING THE CROSS BAR PORTION OF THE BLOCK TO SUPPORT THE BLOCK AND THE STEP, PORTIONS OF THE TENSION ROD ADJACENT THE SIDE RAILS BEING RECEIVED IN THE GROOVE OF THE STEP TO LOCK THE STEP IN POSITION IN THE GAINS.

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