US3407900A

US3407900A - Pole engaging device for ladders

Info

Publication number: US3407900A
Application number: US620069A
Authority: US
Inventors: Hopfeld Henry
Original assignee: Individual
Current assignee: Individual
Priority date: 1967-03-02
Filing date: 1967-03-02
Publication date: 1968-10-29
Anticipated expiration: 1985-10-29

Description

Oct. 29, 1968 H. HOPFELD 3,407,900

POLE ENGAGING DEVICE FOR LADDERS Filed March 2, 1967 Fig.4- //v VE/VTOR HENRY HOPFELD A T TOHWE Y United States Patent 3,407,900 POLE ENGAGING DEVICE FOR LADDERS Henry Hopfeld, 51 Winsliip Ave., Ross, Calif. 94957 Filed Mar. 2, 1967, Ser. No. 620,069 1 Claim. (Cl. 182-107) ABSTRACT OF THE DISCLOSURE In order to positively prevent the slipping of a ladder when it is in a position leaning against a pole, this in vention provides beyond the top rung of the ladder a strap of material with a roughened friction surface bearing against the pole. The strap is longer than the rung so as to assume a curved shape. The ends of this flexible strap are held on the opposite rails of the ladder by brackets. Each bracket has a base flange with bolt holes through it and a wing flange, longitudinal with respect to the adjacent rail. The wing flange has a longitudinal slot immediately adjacent to the base flange. Each end of the strap is extended along the inside of the adjacent wing flange through a longitudinal slot and then under the base flange so that it is pressed between the base flange and the adjacent rail. Each end of the strap between the base flange and the rail has bolt holes aligned with the bolt holes in the base flange and through the adjacent rail, and suitable bolts are extended through the bolt holes to securely hold the brackets and the strap in place. a

BRIEF SUMMARY OF THE INVENTION The result accomplished by this invention is the frictional engagement of the flexible strap with a pole at the top of the ladder, the flexibility of which strap permits a limited conformance to the surface or curvature of the usual pole; by securely clamping the ends of the flexible strap the strap can remain in positive frictional engagement with the pole and prevent lateral shifting as well as vertical slippage of the ladder, thereby preventing accidents which frequently occur when the rung of the ladder is used as a bearing member against a pole.

DESCRIPTION OF THE VIEWS OF THE DRAWING FIG. 1 is a fragmental perspective view showing the flexible strap on the top of the ladder in operative position on the pole.

FIG. 2 is a perspective view of one of the brackets.

FIG. 3 is a fragmental cross-sectional view of about one-half of the strap bearing on the pole, and of the adjacent ladder structure at one end of the strap.

FIG. 4 is a fragmental view of the friction face of the strap.

DETAILED DESCRIPTION The ladder 1, as shown in FIG. 1, is positioned so that it leans against a pole 2. The ladder 1 has parallel rails 3 with the usual rungs 4 therebetween. On the ends of rails 3, projecting beyond the top-most rung 4 is provided a flexible strap 5. This flexible strap 5 has a friction face 6, which at the present time is formed by a series of spaced friction projections 7 for frictionally gripping the pole 2.

Each end 8 of the strap 5 is secured to the inner face of the adjacent rail 3 by means of a bracket 9. Each bracket 9 has a base flange 10. A wing flange 11 extends at an oblique angle from a longitudinal edge of the base flange so that when the base flange 10 is secured ice to the inner face of the adjacent rail 3 then the wing flange 11 projects inwardly of the ladder, the opposite wing flanges 11 converging toward one another and toward the pole 1. In each wing flange 11 is a longitudinal slot 12 immediately adjacent to the adjacent longitudinal edge 13 of the base flange 10. The end 8 of the strap 5 is threaded through the adjacent slot 12. The slot 12 is substantially the same length as the width of the strap 5, and the strap end 8 is bent sharply into engagement with the underside 14 of the base flange 10. The strap 6 is considerably longer than the rung 4 so that the portion of the strap 5 between the slot 12 is longer than the distance between the rails 3, thereby to allow the flexing of the strap into a dished 0r concave curved attitude, as shown in FIGS. 1 and 3, to embrace a circumferential area of the adjacent surface of the pole 2.

Bolt holes are provided through the rails 3 and registering bolt holes 16 are provided through the base flange 10 and strap ends 8. The strap ends 8 are firmly clamped between the respective base flanges 10 and the adjacent inner surfaces of the respective rails 3 by suitable bolts 17.

The herein structure has the advantages of positive frictional engagement with the pole and suflicient flexibility to conform to the adjacent surface portion of the pole; also the mounting of the ends of the strap on the rails of the ladder, by the particular structure of the brackets hereindescribed, prevents the tearing of the strap from the bolts; furthermore, the slotted wing flanges assist in the positioning of the strap in the concave attitude so that it can engage a pole positively .and hold the ladder in various attitudes against a pole, thereby to provide the safety required in many operations where such ladders must be quickly placed in position for immediate use.

I claim:

1. The combination with a flexible strap at the top of and between the facing surfaces of side rails of a ladder, of fastening means, including;

(a) a bracket on the facing surface of each side rail,

spaced from the top of the rail,

(b) a base flange of each bracket overlying said facing surface of the adjacent rail,

(c) a longitudinal wing flange along the edge of each base flange nearest the strap and being at an angle to the adjacent side rail surface,

(d) said wing flange having a slot parallel longitudinally with said side rail,

(e) said flexible strap being longer than the distance between said side rails,

(f) each end of said strap being threaded through the adjacent slot and then bent against the adjacent facing surface thereby to be confined between said base and the adjacent facing surface,

(g) and a fastening element extended through said base, said confined strap end and said rail for clamping said end tightly between said base and said facing surface thereby to hold said strap in a position wherein the transverse plane of said strap is substantially longitudinal relatively to said rails.

References Cited UNITED STATES PATENTS 2,880,789 4/1959 Leibinger 297-385 2,925,877 2/1960 Wright 182-108 3,232,665 2/1966 Von Wimmersperg 297-385 3,243,233 3/1966 Davis 297-385 3,285,659 11/1966 Robbins 297-385 REINALDO I. MACHADO, Primary Examiner.