US1982172A

US1982172A - Automatic adjustment for stepladders

Info

Publication number: US1982172A
Application number: US682975A
Authority: US
Inventors: Hansford J Myers
Original assignee: WILLIAM A WARREN
Current assignee: WILLIAM A WARREN
Priority date: 1933-07-31
Filing date: 1933-07-31
Publication date: 1934-11-27
Anticipated expiration: 1951-11-27
Also published as: FR781633A; GB427950A

Description

Nov. 27, 1934. J MYERS 1,982,172

AUTOMATIC ADJUSTMENT FOR STEPLADDERS Filed July 31, 1935 2 Sheets-Sheet l Nov. 27, 1934. H; MYE S 1,982,172

AUTOMATIC ADJUSTMENT FOR STEPLADDERS Filed July 51, 1933 2 Sheets- Sheet 2 Patented Nov. 27, 1934 UNITED STATES AUTOMATIC ADJUSTMENT FOR STEPLADDERS Hansford J. Myers, Long Beach, Calif., assignor of one-half to William A. Warren, Long Beach,

Calif.

Application July 31, 1933, Serial No. 682,975

3 Claims.

The particular object of the present invention is to provide an improved construction of step ladder which will be strong and durable and which will permit the step ladder to accommodate itself to an uneven surface so that it will be supported firmly and steadily. The invention is illustrated in the accompanying drawings and will be hereinafter fully described, the novel features being particularly defined in the appended claims.

In the drawings,

Figure 1 is a perspective view of a step ladder embodying the present invention.

Figure 2 is a rear elevation of the same.

Figure 3 is a view similar to Figure 2 but showing how the structure accommodates the ladder to an uneven surface.

Figure 4 is a detail of the pivoted brace support.

Figure 5 is a section on the line 55 of Figure 4.

Figure 6 is a detail sectional view of the sliding connection between the brace and the support.

The ladder comprises back legs 1 and front legs 2 and a top or platform 24 of the usual design carried by said legs. The opposed surfaces of the front legs 2 are recessed at stated intervals and steps 9 have their ends engaged in said recesses and secured therein by long bolts or rods 8 disposed below the respective steps with their ends inserted through the legs and fitted with washers 7 and nuts 25 whereby the legs will be caused to clamp the steps and firmly secure the same. At the upper ends of the front legs are secured right angle brackets 6 which are also secured to the underside of the platform or top 24, the bracket being secured to the top by screws and secured to the legs by rivets 26. -The bracket extends rearwardly from the front legs 2 and to the brackets are secured the upper ends of a V-shaped supporting and bracing device, shown at 4, and supported from the back legs. This V-shaped brace is connected to the brackets 6 by rivets 23 which are inserted through holes 21 in the upper ends of the brace and extending through the brace in a plane parallel to the front legs. The brace 4, as clearly shown in Figures 2, 3 and 5, consist of two down- -wardly converging bars which are pivoted together at their lower ends and have said ends made convex, as shown at 27, the arcs having the pivotal connection 17 as their center. A cross brace 3 is pivoted at its ends to the respective back legs 1 by rivets or pins 15 inserted through registering holes 16 and in the upper edge of this brace 3, at the center thereof, is formed a notch 28 having a concave bottom in which the convex lower ends of the brace 4 may seat, a stirrup or clevis 5 being disposed around the bar at the center of the same and having its upper end spanning the brace and secured thereto by the pivots 1'7, as shown and as will be readily understood.

The back legs 1 are provided with longitudinal slots 20 in their upper ends and these slots receive bolts 11 which are inserted through holes 19 in the members of the brace and pass through the respective slots to maintain the brace in proper relation to the legs, washers 10 being disposed upon the bolts between the legs and the brace and at the front sides of the legs, as shown in Figure 1.

A pail shelf 12 is supported at its front end in any convenient manner immediately below the top step 9 between the front legs and extends therefrom to rest upon a rod 13 inserted through openings provided therefor in the members of the brace 4 so that when the ladder is set up for use, the shelf will be supported in a horizontal position.

At a point above the cross brace 3, a hinged brace or spreader 14 is provided to extend'between and be attached to the front legs and the supporting brace 4, this spreader being of wellknown construction and'collapsing as the ladder is folded but automatically locking in extended position when the ladder is set up for use.

In Figure 5, I have indicated a block of wood 28 under one of the back legs of the ladder in order to illustrate how it will accommodate itself to an uneven surface. It will be noted that the bolts 11 carried by the upper ends of the vshaped brace 4 will extend through the slots 20 in the back legs and may slide along said slots while the convex lower ends of the brace, seating in the concave notch in the cross brace 3, will remain in a proper supporting position notwithstanding that said brace 3 may be tilted as the back legs accommodate themselves to an uneven surface. The ladder will be held firm and steady upon an uneven surface inasmuch as the upper ends of the V-shaped brace are secured to the bracket 6 and hence form a direct support for the top or platform of the ladder although the back legs are relatively movable. It will be noted that in a step ladder constructed in accordance with the present invention, it is not necessary to employ wrenches or other tools in order to obtain the desired adjustment of the legs inasmuch as they will automatically shift relative to each other as one or the other legs rests upon a relatively high surface, and the racking strain which would otherwise be imposed upon the ladder resting upon an uneven surface is consequently avoided. The construction of the back part of the ladder throws the weight nearer the bottom of the legs and thereby lessens the tendency to buckle. The construction is simple and ladders embodying the invention may be produced without involving expensive machinery or labor.

Having thus described the invention, I claim: 1. A step ladder comprising front and back legs, a platform connected with the upper ends of the front legs, a cross brace pivoted at its ends to the respective back legs and provided with a seating notch in its upper side at its center, and a supporting brace consisting of downwardly converging side members connected at their upper ends with the platform and having their lower ends seated in the notch in the cross brace, said downwardly converging members having sliding connection with the respective back legs.

2. A step ladder comprising front legs, a platform connected to the upper ends of the front legs, back legs provided with longitudinal slots in their upper ends, a cross brace pivoted at its ends to the respective back legs, a V-shaped supporting brace having its upper ends connected with the platform and its lower end resting on the cross brace and held thereto for relative rocking movement, and guiding elements carried by said V-shaped brace and engaging in the slots in the back legs.

3. A step ladder comprising front legs, a platform connected to the upper ends of the front legs, back legs, a cross brace pivoted at its ends to the respective back legs and provided at its center in its upper side with a concave notch, a V-shaped brace connected at its upper ends to the platform and having its lower end restingin the notch in the cross brace, said V-shaped supporting brace having sliding connection with the upper ends of the back legs, a clevis fitted around the cross brace, and a pivotal connection between said clevis and the lower end of the V-shaped brace.

HANSFORD J. MYERS.