US3009535A - Stepladders - Google Patents

Description

C. E. LARSON Nov. 21, 1961 STEPLADDERS 2 Sheets-Sheet 2 Filed Jan. 13. 1959 INVENTOR. CLAY TON E. LARSON A TTORNE Y United ate This invention relates to stepladders and is more particularly concerned with stepladders possessing unusual stability and unique structural features While requiring a minimum of material for their fabrication.

Field of invention A stepladder exhibiting the characteristics of high stability and minimal structural material requirements has long been desired by both the ladder industry and the consuming public. A commercially acceptable, stable stepladder which would provide a front or treaded section utilizable throughout its full extent without hazard and employing a rear or propping section of a length less lthan that of the front section has been needed for some time.

Various forms of stepladders utilizing a propping section of reduced length have been devised in the past, and structures of this type are described in U.S. Patents 372,967 and 1,368,438. However, the prior known devices of this type leave much to be desired relative to a stable yet practical and economical embodiment of this type of ladder.

ln most of the previous embodiments of stepladders of this general type, the rear section is directly attached to the front section, or is attached by means of a member of negligible length, with the result that the center of balance of the structure is lowered and utilization of the front section above the point of attachment to the rear section is rendered hazardous, so the length which the front section may extend beyond the point of attachment of the rear section is thereby limited.

In addition, a method of eiiiciently attaching and utilizing a bucket rack with this type of structure was rendered difficult of achievement by virtue of the problems encountered in devising pivot and stop means for the bucket rack at a location convenient for the user of the ladder, While still maintaining a structure which might be compactly folded and require a minimum of storage space.

Objects A principal object of this invention is to provide new improvements in stepladders. Further objects include: the provision of stepladders which represent a saving of structural material in that their rear sections are of a length less than that of the front section; the provision of stepladders entailing minimal material requirements while providing excellent stability characteristics; the provision of stepladders possessing minimum structural requirement and maximum stability which may be compactly folded for storage; the provision of a uniting method and member fo-r stepladders which accomplishes the plural functions of uniting the front and rear sections, fully supporting a bucket rack or platform, and locating the center of balance of the structure at a point whereby the entire extent of the front section may be utilized without hazard.

Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereafter. It should be understood, however, that the detailed description, while indicating preferred embodiments of the invention, is given by way of illustration only, since various changes and modications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

General description These objects are accomplished according to the present invention lby forming a stepladder comprising a front section,` a rear propping section of a length less than that of the front section and a uniting member which serves to pivotally attach the rear section to the front section at a point between the center and upper end of the front section with the uniting member also serving as a pivot point for a bucket rack.

Due 'to the pivotal attachment of the front and rear sections, they may assume a compact or folded position in which the side rails of the two sections are parallel, or may be spread apart to form an acute angle. When the sections are spread in order to place the ladder in a stable, independent position for use, their movement about the point of pivotal attachment is limited by means of spreaders which are attached to each pair of opposed side rails.

When the ladder is set-up in the above mentioned position, the bucket rack may be placed in an operable position by moving the rack about its pivot point on the section units lug member, until it comes to rest in a horizontal position, supported by the upper ends of the rear section side rails, which are also attached to the lug member.

The attachment of the rear section to lug members which extend rearwardly from the front section side rails serves to increase the base area of the ladder and to project the center of balance of the structure further upward on the segment of the front section which projects beyond the point of attachment to the lug members, than would be `the case if the rear section were pivoted directly upon the side rails of the front section.

In the preferred form, the ladders described herein are formed from light metal components.

Detailed description A more complete understanding of the new devices of this invention may be had by reference to the accompanying drawings in which: FIG. l is a perspective view of a preferred form of stepladder which is set up in position for use; FIG. 2 is a side view of the same ladder in a folded position; FlG. 3 is a fragmentary sectional View taken along line 3 3 of FIG. l; FIG. 4 is a similar fragmentary sectional View of a modified form of the new stepladders.

Referring in detail to the drawings, `the stepladder basically comprises a front section generally designated at 2 which includes two side rails 4 with a plurality of spaced apart steps 6 and a top tread 8 which are fixed between the side rails l4. In a preferred embodiment of the invention, the steps 6 are recessed at each end to receive the side rails 4 and are provided with projections i0 which parallel the front and rear edges of the side rails Vand are attached thereto by welding, bolts or other suitable means.

Attached to Ithe side rails 4 at a point 12 which is located between the centers and the upper ends of the side rails, are lug members 14 which are discussed in more detail hereafter. In'order to provide for a bucket rack 16 which may pivot about a point located upon the lug member 14 and assume a folded position parallel to the side rails 4 of the front section as shown in FIG. 2 or a horizontal position as illustrated in FIGS. l, 3 and 4, the lug member 14- must be attached to the side rails It at a point below the top of said side rails at least a distance equal to the distance from the pivot point of the bucket rack 16 to the unsupported end 18 thereof. The rear end 20 of the lug members 1-4 are attached aoeasae to the upper ends of the side rails 22 of a rear or propping section 24 of the stepladder. The rear section 24 in addition to the side rails 22, has bracing members 26 which may taken the form of diagonally disposed cross supports as illustrated in FIG. 1 or parallel cross supports (not shown).

In order to render the ladder suitable `for folding to a compact structure in which the front and rear sections are parallel to each other as shown in FIG. 2, one of the points of attachment of the lug member 14 tothe side rails 4 and 2'2 of the front and rear sections is made pivotal while the other point of attachment is xed. FIGS. 3 and 4 illustrate two embodiments of different methods in achieving the pivotal uniting of the front and rear sections of the ladder. In FIG. 3, the lug member 14 is lixedly attached to the side rails 4 of the front section while the opposite end 20 of the lug member 14 is pivotally attached to Ithe side rails 22 of the rear section by means of a pivot pin 2S or other suitable means. In FIG. 4, the lug member 14 is xed to the upper ends of the rear section side rails 22 while pivot means 30 are used to `attach the other end of the lug member to the side rails 4 of the front section.

When it is desired to convert the stepladder from its folded form in which the side rails 4- and 22 of the front and rear section are parallel as shown in FIG. 2, to the open or set-up position of FIG. l in which the side rails 4 yand 22 form an acute angle, the side rails are merely spread apart to the proper angle and restricted from further movement about the pivot point by means of a spreader 32. While the spreader 32 illustrated in FIG. l comprises a rigid spreader which it attached at each end and hinged in the middle, a chain attached at each end to the side rails 4 and 22, or pivotally attached to the side rail at one end with means at the other end for a disengageable attachment to the other side rail, or any conventional spreader, may be employed.

The lug member 14 is best illustrated in FIGS. 3 and 4 which demonstrate dilerent embodiments of the invention. As shown in FIG. 3, each of the two lug members 14 comprises a at, oblong plate which is lixedly attached to the side rail 4 of the front section by any suitable means such as welding, and projects rearwardly therefrom with the other end 20 being pivotally attached by a pivot pin 28 or the like to the upper end of the rear section side rail 22. The lug member 14 is further provided with means 34 for the pivotal attachment of the bucket rack 16. Said means of pivotal `attachment 34 may comprise a socket, aperture or other suitable means for the reception of a pivot point which projects laterally from the bucket rack 16. The means of pivotal attachment 34 is so spaced labove the point of attachment of the lug member 14 to the rear section side rails 22 and toward the point of attachment of the lug member 14 to the front side rails 4, that the bucket rack 16 may pivot from a folded position parallel to the front section side rails 4 to rest upon the upper ends 36 of the rear section side rails 22 which serve to support the bucket rack in a horizontal position as shown in FIGS. 1, 3 and 4.

Thus, it may be seen that the invention provides a stable ladder structure which may be compactly folded `for storage. In addition, a minimum of structural material is required in View of the fact that the rear or propping section of the stepladder is of a lesser length than the front or treaded section. Novel uniting means are also provided in that direct attachment of the rear section to the front section with a resultant lowering of the center of balance of the structure and a decrease in stability are avoided by means of an attachment member which projects rearwardly of the front section and serves both to receive the attached rear section and to pivotally support a bucket rack which may be compactly folded for storage or placed in a horizontal, operable position in which it is supported by the rear section of the ladder.

I claim:

l. A stepladder comprising a front section including two side rails and a plurality of spaced apart steps fixed between the side rails, a rear propping section comprising two side rails and brace members for holding the side rails in spaced apart relation, a pivotally supported bucket rack, means for pivotally attaching the rear section to the front section comprising a lug member carried upon one of the side rails of the front section -above the center of the side rail and below the top of the side rail at least a distance equal to the distance from the pivot point of the bucket rack to the unsupported end thereof, the lug member extending rearwardly of the back edge of the side rail, a second lug member similarly attached to the other side rail of the front section, one of the side rails of said rear section, Ibeing carried at its upper end on the inside of one of said lug members, the second side rail of the Irear section being similarly carried on the second lug member, said bucket rack being slightly narrower in width than the inside distance between said lug members, said bucket rack being located between said lug members and being pivotally attached to said lug members at a point which is so located above the point of connection of the rear section side rails and toward the point of connection to the front section side rails that the upper ends of the rear section side rails act as the sole stop means for holding the bucket rack in a horizontal position when the rack is folded down, and spacer means for supporting the front and rear section side rails in a spaced apart relation.

2. A stepladder comprising a front section, including two side rails and a plurality of spaced apart steps fixed between the side rails, a rear propping section comprising two side rails and brace members for holding the side rails in spaced apart relation, a pivotally supported bucket rack, means for pivotally attaching the rear section to the front section comprising a lug member fixed upon one of the side rails of the front section above the center of the side rail and below the top of the side rail at least a distance equal to the distance from the pivot point of the `bucket rack to the unsupported end thereof, the lug member extending rearwardly of the back edge of the side rail, a second lug member similarly fixed upon the other side rail of the front section, one of the side rails of said rear section being pivotally attached at its top on the inside of one of said lug members, the second side rail of the rear section being similarly attached to the second lug member, said bucket `rack being slightly narrower in width than the inside distance between said lug members, said bucket rack being located between said lug members and being pivotally attached to said lug members at a point ywhich is so located above the point of attachment of the rear section side rails and toward the point of attachment of the front section side rails that the upper ends of the rear section side rails act as the sole stop means for holding the bucket rack in a horizontal position when the rack is folded down, and spacer means for supporting the `front and rear section side rails in a spaced apart relation.

3. A stepladder comprising a front section including two side rails and a plurality of spaced apart steps fixed between the side rails, a rear propping section comprising two side rails and brace members for holding the side rails in spaced apart relation, a pivotally supported bucket rack, means for pivotally attaching the rear scction to the front section comprising a lug member pivotally attached to one of the side rails of the front section above the center of the side rail and below the top of the side rail at least a distance equal to the distance from the pivot point of the bucket rack to the unsupported end thereof, the lug member extending rearwardly of the back edge of the side rail, a second lug member similarly attached to the other side rail of the front section, one of the side rails of said rear section being fixed at its upper end on the inside of one of said lug members, the

second side rail of the rear section being similarly attached to the second lug member, said bucket rack being slightly narrower in width than the inside distance between said lug members, said bucket rack being located between said lug members and being pivotally attached to said lug members at a point which is so located above the point of attachment of the rear section side rails and toward the point of attachment of the front section side rails that the upper ends of the rear section side rails act as the sole stop means for holding the bucket rack 1 in a horizontal position when the rack is folded down, and

spacer means for supporting the front and rear section side rails in a spaced apart relation.

References Cited in the le of this patent UNITED STATES PATENTS 847,919 Douds Mar. 19, 1907 964,324 Spaulding July 12, 1910 1,368,438 Jacob Feb. 15, 1921 1,821,075 Peters et al. Sept. 1, 1931 2,899,008 Larson Aug. 11, 1959

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