US2481581A - Extension stepladder - Google Patents

Description

H. EHNHUUS EXTENSION STEPLADDER Sept. 13, 1949-.

Filed Dec. 17, 1945 HHPTV/G E /W555 67 BY- Patented Sept. 13, 1949 UNITED S TAT ES QF'Fi-C'E V EXTENSION STEP-LADDER Hartvig Ehnhuus, BrooklymN. Y.

Application December 17, 1945; Serial N0. 635,52 1

1 Claim. 1

This invention relates vto ladders and in particular to a type that can be lengthened for use on-asupportin surface that is uneven.

A particular objec'to'f my invention is to provide a device that can be attached to ladders in present use, or can be applied to ladders in the course of manufacture to provide an extension for either the front or back legs thereof or both, or to provide an adjustable feature that can be used to vary the length 0f any one of the four legs of the ladder when the sameis used on a very uneven surface.

A further and equally important object of my invention is to provide in connection with the foldabl-e step ladder, a safety device that permits use of the ladder on stairways so that ceiling lights andwalls-ma-y be painted or cleaned without the necessity of puttingup a supporting scafiold in the stair well which is necessary where the present ladderszare employed that have no adjustable leg features incorporated.

A still further object of my invention is to make up a device that can be applied to the legs of the ladder by the purchaser of the device without complicated effort or instructions; to provide a device that is simple in structure, can be made and sold at a moderate cost, will provide a substantial support without slippage of the parts and will effectively lock the extension parts in any adjusted position securely So that collapse will be prevented.

With these and other objects in View, the invention comprises certain constructions hereinafter described and then particularly pointed out in the claim and a preferred embodiment of my invention is illustrated in the accompanying drawings, in which:

Figure 1 is a view in side elevation of a folding type step ladder showing the application thereto of my invention,

Figure 2 is an enlarged fragmentary view of the lower end of one of the front legs showing the extensional use of the device on a stairs.

Figure 3 is a view taken from the rear of the leg as illustrated in Figure 2 showing the attachment of the guide channe1 forming a part of my invention,

Figure 4 is a View somewhat similar to Figure 2 showing the back leg extended to compensate for an uneven surface,

Figure 5 is an enlarged section taken on the line 5--5 of Figure l, and

Figure 6 is an enlarged section taken on the line B6 of Figure 2.

Referring to the drawing in detail, It indicates :2 a'step'i-adder of the foldingttype comprisingthe front leg structure. including sides [:2 land-steps l-Bwcon'necti-ng the latter and secured thereto the tie rods or connecting bolts M, as well as-ot-her 1 suitable step fastening means which is: is not deemed necessary to show.

The sides 122 are secured-by a brace-plate l5 to thetop -IE of the ladder, the bracegplate providing means in which are pivotally mounted astat l1, the rearor bracing leg structure 18 of the ladder, which consists-of the side pieces-L9 suitablyjcined and carrying .a tray-1:91A- which folds-about the pit 2E; and foldably associated with the front leg structure I I by t-he'hinge arms'2 l In order to extendor lengthen the front leg structure ii, "I have provided at the lower end of seach of thefront legs or sides +2: aguide channel 22 which is l'ongienough to-constitute asleeveand is shaped-.inwcrosssection :as shown in Figure 6 to preserrta rside portionrZfi and edge flanges 24 in opposed relation to firmly fit the side of the legs and the edges thereof. The channels are held in place by the screws 25 or other fastening means to provide a, passage through which is mounted for sliding movement an extension member 26 which is exactly as wide as the side piece of the ladder and snugly fits within the passage formed by the channel and the side of the leg l2 so that it can be manually moved up and down for adjustment beyond the end of the leg l2 as shown in Figure 2, to extend the ladder structure at the front thereof in the event that the ladder is to be used on a stairs for instance. It will be noted that a step 21 of the stairs will provide a step for the ladder in its extended portion. The channel member 22 has welded or otherwise fastened thereto as at 30, an internally threaded nut 3| which is aligned with a similar opening in the guide channel to receive a threaded end 32 of an adjusting handle 33 which is manipulated to jam the extension piece 26 and securely hold the same in its adjusted position. The channel member may be made of any suitable gauge sheet metal and the extension member on its under side is grooved longitudinally thereof as at 34 to pass over any projection on the sides l2, such as the 3 leg 38 to increase the length of each leg l9, the extension being grooved on its inner face as at 39 to pass over any obstruction on the side of the legs I 9. A threaded nut 40 is Welded or otherwise attached to the channel in alignment with an opening in the latter to permit the use of a threaded adjusting handle 4| for the purpose of holding the extension leg at any desired position Of adjustment. The extension legs 38 fit snugly into the channel guides so that there is no sidewise play that would make the ladder wobble and endanger the person working on the same. The length of the guide channel is a factor in bracing the ladder and making the extenrsion legs safe at every degree of adjustment as the channels firmly hold the extension legs at the sides and edges to provide true sliding movement.

My invention is not to be restricted to the precise details of construction shown since various changes and modifications therein may be made without departing from the scope of the invention or sacrificing the advantages derived from its use; V i

What I claim is:

The combination with a step-ladder having fold-able frame parts including relatively pivoted front and rear flat strip legs, means for connecting the rear legs together and steps for connecting the front legs together: of an elongated metal channel piece substantially U-shaped in cross section and extendingupwardly along each leg from the lower end thereof to provide an ex-'- tended sleeve having a side portion paralleling the outer side surface of the leg and opposite edge flanges fitting over and against the front and rear edge surfaces of the leg, said channel being as wide as the leg, means for securing the edge flanges to the front and rear surfaces of the leg to space said side portion of the channel piece 4 from the outer surface of the leg to present a vertical open ended passage alongside said leg, an elongated fiat extension piece substantially as Wide as the leg for frictional abutment throughout its contact surface with said leg and extending through said channel passage and being substantially longer than said channel piece said side portion having an opening therein, an internally threaded nut securedto said side portion in alignment with said opening, a handle having an end threaded for adjustable engagement in ,the nut and jamming engagement'with the extension piece to force the under surface thereof in that portion of its length in engagement with the leg into frictional holding contact with the outer side surface of the leg and to cause the side edges of the channel piece to frictionally engage the side edges of said extension piece whereby the extension may be frictionally secured at any position of adjustment with respect to that portion of'said'leg, engaged thereby, and said channel piece, said extension piece and the holding means associated therewith being wholely mounted on the side and outer faces of the legs of the ladder to maintain the inner faces of said legs unobstructed.

HARTVIG EI-lNHUUS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Bengert Oct. 17, 1944

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