US2720354A - Adjustable ladder for washing windows - Google Patents

Description

Oct. 11, 1955 F. G. STANLEY 2,720,354

ADJUSTABLE LADDER FOR WASHING WINDOWS Filed Sept. 9, 1952 INVEN TOR.

Frank G. Si'cJn lg United States Patent ADJUSTABLE LADDER FOR WASHING WINDOWS Frank G. Stanley, Salem, Oreg.

Application September 9, 1952, Serial No. 308,615

3 Claims. (Cl. 228-25) My invention pertains to ladders, and relates particularly to an adjustable sectional ladder adapted particularly for use in washing windows but providing equal advantages for other purposes.

It is a principal object of my invention to provide an adjustable sectional ladder in which the plurality of sections are constructed in but two standard sizes which are interlocked detachably but securely by novel means associated with the rungs thereof.

Another important object of my invention is the pro vision of a ladder with which is associated novel adjustable spacer means, for positioning the ladder at proper distances from the vertical surface to be worked upon.

A further object of my invention is the provision of a ladder in which the rungs function to secure the aforementioned adjustable spacer means pivotally to the ladder.

A still further object of my invention is to provide a ladder in which the aforementioned spacer means also functions as a mounting for a tray in which tools may be deposited for selective use when the ladder is in operative position.

A still further object of my invention is the provision of a sectional ladder which is of simplified and therefore economical construction, which is strong and durable, which is assembled and disassembled; with maximum facility and speed, and is readily collapsed to a compact and light weight unit for convenient handling in transport.

These and other objects and advantages of my invention will appear from the following detailed description taken in connection with the accompanying drawing, in which:

Figure 1 is a foreshortened front elevation of a ladder embodying the features of my invention;

Figure 2 is a foreshortened side elevation of the ladder as viewed from the left in Figure l;

Figure 3 is a plan view of the spacer means forming a part of the ladder of my invention; and

Figure 4 is a fragmentary side elevation of the spacer and ladder illustrated in Figure 3.

The ladder comprises a plurality of rather short sections, preferably about six feet in length. Half of the number of sections are slightly narrower in width than the others for purposes of interengagement therewith, as explained in detail hereinafter. Thus, the wider sections include spaced parallel side rails 1 and 2 to which the 0pposite ends of a plurality of rungs 3 are secured in any suitable manner. The rungs are uniformly spaced longitudinally of the side rails, preferably about one foot apart.

The narrower sections of ladder include the spaced side rails 4 and 5 and the longitudinally spaced rungs 6 constructed in manner similar to the wider sections. The narrower sections are so proportioned that their overall width is slightly less than the distance between the inner sides of the rails 1 and 2 of the wider sections, as shown in Figure 1 of the drawing.

Two pairs of hooks 7 are secured to one longitudinal edge of each of rails 4 and 5 of the narrower ladder sections adjacent one end of the ladder. These hooks are 2,720,354 Patented Oct. 11, 1955 offset from said edge and project toward the said end of the ladder and are positioned to engage an adjacent pair of rungs 3 of a wider ladder section, as best shown in Figure 2, when the narrow and wide sections are placed in overlapping arrangement. Two other pairs of similar offset hooks 8 are secured to the opposite longitudinal edge of the rails 4 and 5 adjacent the opposite end of the narrow ladder section. These hooks project toward the said end of the ladder and are positioned to engage an adjacent pair of rungs 3 of a second Wider ladder section.

It is to be noted that although the drawing shows the hooks 7 and 8 engaged with the two rungs 3 adjacent the ends of the two wider ladder sections, the uniform spacing between all of the rungs 3 permits the hooks to be engaged with any desired adjacent pair of rungs, thereby affording adjustment of the overall length of the ladder in increments of one foot, i. e. the spacing between adjacent rungs.

It is to, be noted further that the narrow ladder sections carrying the hooks 7 and 8 are reversible end for end, thereby rendering the assembly of sections most convenient and rapid since there is no requirement to orient the narrow sections in one direction. This construction also permits the entire assembled sections to be reversed end for end.

There is also provided for use with the ladder described hereinabove a spacer unit adapted to space the upper end of the ladder a proper distance away from the vertical wall or other structure against which the ladder is placed. This spacer unit comprises a pair of legs 9, 10 secured together in spaced relation by the transverse bars 11, 12. The legs are each provided at their inner ends with a bifurcated section 13 proportioned and arranged to be inserted over one of the rungs 6 adjacent the side rails 4, 5. The terminal ends of the bifurcated sections are provided with axially aligned apertures which are adapted to removably receive a pin or bolt 14 which functions to pivotally secured the bifurcated section to the rung 6. Thus, the bifurcated sections 13, and their cooperating bolts 14 serve as clevises by which to pivotally secure the legs 9, 10 to the rung of the ladder. A length of chain 15 is secured at one end to each bolt 14 and at the opposite end to a lug 16 mounted on the legs 9, 10 to prevent accidental loss of the bolts and to maintain thelatter within convenient access. i

A brace 17" is secured to each leg and projects downward at an oblique angle therefrom for contact at its free end 18 against the edge of the side rails 4, 5 of the ladder, as best shown in Figure 4. These braces are so arranged that when the free ends 18 thereof abut against the rails 4, 5 the angle formed between the legs 9, 10 and the said rails is about Since the ladder assembly is disposed at a slight angle with respect to the vertical wall or other support against which it is placed, the legs 9, 10 are thereby disposed substantially normal to said wall or support. The legs diverge from their bifurcated ends 13, as shown in Figure 3, and their ends are provided with rubber or other protective caps 19 which serve as grippers to prevent displacement of the ladder. These caps also prevent scratching or other damage to the surface against which they are placed in contact.

It is to be noted that the ends 18 of the braces 17 are not secured to the side rails of the ladder but merely abut against them. This feature permits the legs 9, 10 to be rotated upwardly from such abutting position but prevents the legs from collapsing downwardly. In this manner the legs may serve as a sliding support while extending the ladder and yet the legs may be swung upwardly to adjust the distance and angle between a supporting surface and the ladder in order to place the operator at the most convenient position for work.

There is also provided on'the spacer unit means for supporting various tools or implements used by the operator when stationed upon the ladder. This means is illustrated in Figures 3 and 4 of the drawing as a pair of spaced U-shaped brackets 20 secured transversely between and depending below the bars 11, 12. These brackets function as a tray upon which to deposit the said tools for convenient access to the operator. If desired a wire mesh screen may be secured to the brackets to form a basket. A further alternative construction is to secure to the bars 11, 12 a solid box structure. Thus, the tray may take various forms, although I have found that the brackets 20 are well suited for supporting the conventional implements used for cleaning windows.

From the foregoing it is believed apparent that the ladder construction of my invention provides for the rapid and easy assembly of the sections to form a strong and sturdy unit and also affords ready disassembly into a compact package for convenient transport. The assembly of the ladder sections is accomplished by merely engaging the pairs- f hooks 7 and 8 at each end of each narrow section over the desired pairs of rungs 3 of the wide ladder sections, as best shown in Figure 2 of the drawing. Adjustment to desired height is achieved by proper selection of the engaging rungs 3. Only two sizes of ladder sections are required, i. e. the wide and narrow sections, and any number of these may be connected together alternately to provide a ladder of any desirable height.

The combined spacer unit and tray is attached to the ladder with maximum facility merely by slipping the clevis ends 13 of the legs 9, over the desired rung 6 and engaging the bolt 14 in the aligned holes provided in said clevis ends. The brackets 17 maintain the spacer unit extended while the ladder is raised into position.

In the event it is desired to shorten the distance between the upper end of the raised ladder and the vertical support with which the spacer unit is in contact, the operator merely pushes the upper end of the ladder away from the support momentarily and pivots the spacer unit upward to the desired angle.

It will be apparent to those skilled in the art that various changes in the structural details described hereinbefore may be made without departing from the scope and spirit of my invention. Accordingly it is to be understood that the foregoing description is primarily illustrative and is not to be construed in a limiting sense.

Having now described my invention and the manner in which the same may be used, what I claim as new and desire to secure by Letters Patent is:

1. A ladder comprising a plurality of wide and narrow spaced cross rungs arranged in a common plane, two pairs of hook means secured to one edge of the side rails of the narrow sections adjacent one end thereof, and two pairs of hook means secured to the opposite edge of the side rails of the narrow sections adjacent the opposite end thereof, the hook means projecting toward the respective ends of the narrow sections and spaced apart a distance equal to the spacing between the rungs of the wide sections, whereby each two pairs of hook means is engageable with any adjacent pair of rungs of the wide sections for adjustably securing the narrow and wide sections together.

2. A ladder comprising a pair of wide sections and a narrow section each having parallel side rails and uniformly spaced cross rungs arranged in a common plane, two pairs of hook means secured to one edge of the side rails of the narrow section adjacent one end thereof, and two pairs of hook means secured to the opposite edge of the side rails of the narrow section adjacent the opposite end thereof, the hook means projecting toward the respective ends of the narrow section and spaced apart a distance equal to the spacing between the rungs of the wide sections, whereby each of two pairs of hook means is engageable with any adjacent pair of rungs of the wide sections for adjustably securing the narrow and wide sections together.

3. A ladder comprising a wide section and a narrow section each having parallel side rails and uniformly spaced cross rungs arranged in a common plane, two pairs of hook means secured to one edge of the side rails of the narrow section adjacent one end thereof, the hook means projecting toward the said end of the narrow section and spaced apart a distance equal to the spacing between the rungs of the wide section, whereby the two pairs of hook means are engageable with any adjacent pair of rungs of the wide section for adjustably securing the narrow and wide sections together.

References Cited in the file of this patent UNITED STATES PATENTS 886,737 Taylor May 5, 1908 1,155,125 Blankenhagen Sept. 28, 1915 2,592,006 Burke Apr. 8, 1952 FOREIGN PATENTS 268,709 Great Britain Apr. 7, 1927 468,439 France Apr. 24, 1915

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