US2726901A

US2726901A - Safety step for ladder

Info

Publication number: US2726901A
Application number: US348208A
Authority: US
Inventors: Allen F Newman; Ernest H King
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-04-13
Filing date: 1953-04-13
Publication date: 1955-12-13
Anticipated expiration: 1972-12-13

Description

A. F. NEWMAN ErAL' SAFETY STEP FOR LADDER Dec. 13, 1955 Filed April 13, 1953 INVENTORS ALLEN F. NEWMAN. By ERNEST I-LKING. AI'TcRNEY United States PatentQ 2,726,901 7 SAFETY STEP FOR LADDER Allen F. Newman and Ernest H. King, Detroit, Mich.

Application April 13, 1953, Serial No. 348,203

3 Claims. (Cl. 304-315) This invention relates to extension ladders and has particular reference to a safety step for use with such a ladder.

An object of the invention is to generally improve devices of that character, and to provide a safety step which is simple in construction, economical to manufacture, and efficient in use.

Another object of the invention is to provide a safety step which may be adapted to ladders of different size and physical characteristics.

Another object of the invention is to provide a device of the character indicated which is constructed with adjustable means for locking the step in position on a ladder.

Another object of the invention is to provide a safety step which may be readily attached to and removed from a ladder, and one which is particularly suitable for use with metal ladders.

Another object of the invention is to provide a safety step, which is constructed and arranged so that the more pressure that is exerted on the step when in use, the tighter it will grip the side rails of the ladder, whereby to insure its remaining in position under all working conditions.

The foregoing and other objects and advantages of the invention will become more apparent as the description proceeds, reference being made from time to time to the accompanying drawing, in which drawing:

Fig. 1 is a fragmentary view of a ladder, to which is attached the device embodying the invention.

Fig. 2 is a top plan view of the device illustrated in Fig. 1.

Fig. 3 is a section taken substantially on the line 3-3 of Fig. 1.

Fig. 4 is a section taken substantially on the line 4-4 of Fig. 1.

Fig. 5 is a section taken substantially on the line 5-5 of Fig. 2.

Referring now more particularly to the drawing, it will be understood that in the embodiment herein disclosed, the reference characters 7 and 8 indicate the side rails of a conventional aluminum ladder, having rungs 9 and 10, and to which ladder is attached the device embodying the invention, which device consists of a metal plate 11 which may be made of aluminum or other suitable material, and which is provided on its top surface with ribs 12, which serve as means to reinforce the plate and frictional elements to prevent the operators foot from slipping while the step is in use. The plate ii has depending

side flanges

13 and 14, which further serve to reinforce the structure, and act as bearing elements for the locking mechanism hereinafter described.

The locking elements for the step 11 consist of a pair of

rods

15 and 16 which are bent and rebent as shown to form

cradles

17 and 18 for receiving the side rails 7 and 8 of the ladder. The

cradles

17 and 18 serve to prevent the step from being dislodged forwardly or rear- "ice 2 wardly from the side rails 7 and 8, and also serve to prevent the movement sideways of the step with reference to the ladder, particularly when pressure is being exerted on the top of the step as hereinafter described. The respective ends of the

rods

15 and 16 are bent inwardly toward each other to form pivots which are extended through

holes

19, 20, 21 and 22 formed in the

flanges

13 and 14, in which holes they are free to rotate. One end of each rod has an extension 23-24 thereon, each extension 23-24 having a curved portion 25-26, which is adapted to ride on top of the rung 29, as shown in Figs. 3, 4, and 5. The engagement of the curved portions 25-26 with the rung 9 also helps to prevent the forward or rearward movement of the step with respect to the ladder. The convex face of each curved portion 25-26 is arranged to contact the lower face of the step 11, which puts tension on the

rods

15 and 16 when they are swung outwardly as shown by the dotted lines in Fig. 5. This is particularly advantageous when the step is being used on a comparatively wide ladder, for under such conditions any increased pressure on the top of the plate 11 will increase the gripping action of the

cradles

17 and 18 with the side rails 7 and 8, because of the triple bearing contacts between each rod and step.

It will be noted that the

extended ends

23 and 24 of the rods are inclined inwardly with respect to a line drawn through the holes 19-21 and 20-22 (Fig. 3) which enhances the resilient action between the parts and permits the

cradles

17 and 18 to be rocked outwardly until the straight portions of the rods lie substantially parallel with the upper face of the step, as shown by the lowermost dotted lines in Fig. 5. Thus it will be seen that this safety step may be attached to ladders of greatly varying widths with equal facility. The operation of the device is obvious from the foregoing.

Having described our invention, what we claim and desire to secure by Letters Patent is:

l. A safety step for use with a ladder having a pair of side rails and rungs therebetween, comprising a plate like element to be received on one of the rungs of said ladder, said plate like member having a cradle pivoted at either end thereof for movement in a plane parallel to the axis of the plate, each of said cradles being arranged to engage a side rail of said ladder, whereby to secure said plate against lateral movement, each of said cradles consisting of a rod having its free ends bent inwardly toward one another to form pivots, one of said pivots having an extension angularly inclined with respect to the other, said extension having a curved portion arranged to engage the'top of said rung and the under side of said plate.

2. A safety step for use with a ladder having side rails and a rung, comprising a plate like element arranged to be supported by said rung, said plate having downwardly extending flanges, openings in said flanges for receiving the ends of a pair of rods, rods pivoted in said openings, each said rod being bent intermediate its end to form a cradle for receiving one of the side rails of said ladder, whereby to prevent the lateral movement of said plate, one end of each of said rods being angularly inclined with respect to the opposite end of said rod, there being a curved portion on said angularly inclined end adapted to contact said rung, and be contacted by the underside of the step, whereby to put said rod under tension.

3. A safety step for a ladder having side rails and a rung, comprising a metal plate having its longitudinal edges directed downwardly, apertures in the downwardly directed portions of said plate, a rod having its ends inturned to form pivots, which said pivots are rotatably received in said apertures, one of said pivots of each rod having an angularly directed extension thereon, said angularly directed extension having a curved mid-section arranged to receive the rung of said ladder and be contacted by the underside of the step to put tension on said rod, the main sections of said rods being bent and rebentto form cradles for receiving the side rails of said ladder, '5

References Cited in the hie of this patent UNITED STATES PATENTS Riegger Mar. 1, Bush Mar. 24, Postal June 10, Putnam Jan. 18, Yothers Feb. 4,

Newman et a]. Oct. 31,