US3303906A - Safety ladder - Google Patents

Description

Feb. 14, 1967 w. BOUWMEESTER ETAL 3,

SAFETY LADDER Filed Oct. 7, 1964 2 Sheets-Sheet 1 INVENTORS WILLIAM BOUWMEESTER ABRAH AM BE R G 4 ATTORNEYS 1967 w. BOUWMEESTER ETAL 3,

SAFETY LADDER Filed Oct. 7, 1964' 2 Sheets-Sheet 2 INVENTOR WILLIAMBOUWMEESTER BYABRAHAM BERG 7774 ATTORNEYS United States Patent 3,303,906 SAFETY LADDER William Bouwmeester, Juniper St., and Abraham Berg, 9 Ingram Drive, both of Hicksville, N.Y. 11801 Filed Oct. 7, 1964, Ser. No. 402,183 6 Claims. (Cl. 182161) This invention relates to a ladder for use in conjunction with pools, tanks or other similar structures to provide steps for access to the pool or tank which steps automatically retract upon disuse so that a smooth surface is presented in order to prevent children or other unauthorized persons from using the ladder inadvertently or otherwise unless they understand its operation.

The primary purpose of this invention is to provide access to a pool or tank and at the same time furnish a structure which will substantially prevent small children from using the ladder without adult aid thereby lessening the possibility of accidents.

The object of our invention is to provide a ladder in which a set of steps may be made operable and in which the steps, after use, automatically and slowly resume their original inaccessible position.

A further object is to provide a ladder of the character described in which actuation of a single handle causes a set of steps to assume an operative position and, when pressure is released from the steps, to resume their original locked position.

Another object is to provide a structure of the character described in which a set of the steps may be operated by hydraulic means.

A further object is to provide a ladder of the character described in which a set of the steps are first locked in operative position, and at a predetermined time, are unlocked from said position and returned to their original locked position.

A further object is to provide a structure in which the above and other objects may effectively be attained as will appear from the detailed specification which follows:

Broadly our invention comprises a ladder in which the steps may be manually placed in usable position through the operation of a single handle and in which the steps will automatically assume an inoperative position when weight on the first-named steps has been removed therefrom.

Practical embodiments of my invention are illustrated in the accompanying drawings in which:

FIG. 1 represents, in side elevation, a ladder constructed according to our invention and placed with respect to a pool or tank so that access thereinto by means of the ladder is provided;

FIG. 2 represents an end view of the ladder illustrated in FIG. 1;

FIG. 3 represents a portion of the ladder modified to be operated by a hydraulic mechanism, said portion being partly in section and partly broken away;

FIG. 4 represents a fragmentary section on an enlarged scale taken on the line IVIV of FIG. 2, looking in the direction of the arrows, the operating handle having been removed;

FIG. 5 represents an end view of the fragment shown in FIG. 4; and

FIG. 6 represents an end bracket, shown in detail, removed from its supporting structure.

Referring to the drawings in which similar parts are given the same numerals, a pair of front longitudinal supporting members is denoted by 23 and a pair of rear supporting longitudinal members is denoted by 24. These parts are held in the desired angular relationship by two end pieces 25 and movable steps 10 are spaced between members 28 to present a normally fiat surface.

3,303,906 Patented Feb. 14, 1967 Pivoted on a rod 2 is a handle 1 which turns the rod 2 said rod being supported in elements 29, to throw the lever 3 and the latter, in turn, actuates the lever 4 which is connected thereto to pull down the longitudinal member 5 against the tension of spring 14 which is mounted at one end on the horizontal 28 and passes around a pulley 7 on the member 5. (See FIG. 4.) The other end of spring 14 is attached to a bracket 27 on the bottom of top step 12.

Also attached to the member 5, through arms 9 pivoted thereon, are the steps 10. Said steps 10 are normally pivoted at the other end in the side longitudinals 23 as is shown in FIGS. 1, 3 and 4.

Also attached to bracket 27 on the bottom of the step 12 is a spring 15 which is extended over and across the rod 2 and said spring is afiixed at its other end to the member 3 for purposes set forth below.

The operation of handle 1 rotates rod 2 which actuates the interconnected members 3 and 4 to cause a downward swing of element 5. Due to said downward motion the steps 10 are swung until the parts assume the positions shown in FIG. 4 where the angle iron 11 engages the top step 12 at which time the steps 10 are temporarily in their horizontal or usable position on elements 9.

When the weight of the user has been removed from the last of steps 10, spring 14, operating around pulley 7 on member 5 will cause member 5 to rise and this will insure the pivoting of steps 10 in members 23 to a position in which they are in parallel with said members 23, intermediate elements 28 and with each other. The air or other fluid cylinder 13 acts as a buffer against the force of spring 14 and allows the steps to move slowly to their initial position. It will thus be seen that no step 10 will move while any step 10 is being used but all will start to move when the weight of the user has been removed from the last step 10.

The locking of the steps in inoperative position is aided by the spring 15 which insured that the latch mechanism, including the members 3 and 4, has gone past the center position as is illustrated in FIGS. 3 and 4.

A modified form of our invention is shown in FIG. 3 in which a member 20, and a hydraulic cylinder 21 provided with a piston 21a pivoted to member 20 in order to operate same, are used as replacement for the handle 1.

An operating valve 22 permits water under pressure, as from the hose 26, to operate the piston 21:: through the cylinder 21 which will cause member 20 to actuate levers 3 and 4 and swing the steps 10 to their usable position as was described above.

It will be understood that the operation of the mechanism and the location of the steps is substantially identical in the two structures except as outlined immediately above.

In this modified form, illustrated in FIG. 3, when the weight of the user has been removed from the steps 10 the springs 14 and 15 will cause the steps to return to their original position with respect to members 23 by lifting members 5 and forcing piston 21a back into cylinder 21 which is provided with a small release hole (not shown) in order to bleed the cylinder through outer hose 6.

When one desires to leave the tank this is done by ascending the permanent steps denoted by 16 which are used until the handle 1, or the hydraulic mechanism, is actuated to cause the steps 10 again to move to usable position. When the weight of the user has been again removed, the steps 10 will resume their original position.

It will be seen from the above that we have provided a substantially fool-proof ladder for use in connection with pools, tanks or the like in order that the chances for accidents may be minimized and the structure may be operated only by those having knowledge of its opera tion.

It is contemplated that the operating mechanism will normally be placed beyond the reach of children.

Since it is evident that various changes may be made in the form, construction and arrangement of the several parts without departing from the spirit and scope of our invention, we do not intend to be limited to the specific embodiments herein shown and described except as set forth in the appended claims.

What We claim is:

1. In a safety ladder structure comprising a pair of opposed, longitudinal, supporting members, a set of movable steps in said pair of members, a linkage operatively connected to the movable steps to provide for movement of the latter between usable and inoperative positions, locking means connected to said linkage to lock said steps in inoperative position, and means manually actuated to simultaneously release the locking means and operate said linkage to place the steps in operative position.

2. In a structure of the character described comprising a pair of opposed longitudinal supporting members, a set of steps movable between usable and inoperative positions in said pair of members, operative means connected to the movable steps for placing the latter in a usable position, manual means comprising a hand lever for actuating said last-na1ned means, said operative means comprising interconnected levers affixed to the hand lever and movable steps, locking means cooperating with said interconnected levers for urging the latter into a locked position to hold the steps in inoperative position, and further means acting on said operative means for restoring the movable steps to their original inoperative position when the weight of a user has been removed therefrom.

3. In a structure according to claim 2 in which the means for restoring the steps to their inoperative position comprises a spring biasing the steps to their inoperative position, said locking means comprising a spring afiixed to said interconnected levers for holding the latter in said locked position.

4. A structure of the character described comprising pairs of opposed longitudinal supporting members, a set of movable steps normally locked in parallel with one pair of longitudinal supporting members, a set of fixed steps in the opposed pair of supporting members, means for swinging the first-named set of steps to a horizontal position and other means for automatically retracting the movable steps to their original locked position when the weight of a user has been removed therefrom and fluid means for braking the retracting movement of said steps.

5. The combination according to claim 4 in which the means for swinging said steps include hydraulic apparatus connected thereto.

6. In a safety ladder comprising a pair of opposed longitudinal supporting members, a set of movable steps normally locked in parallel with said pair of longitudinal supporting members, means for swinging said set of steps to a horizontal position and other means for automatically retracting the movable steps to their original locked position when the weight of a user has been removed therefrom, and fluid means for braking the retracting movement of said steps.

References Cited by the Examiner UNITED STATES PATENTS 488,990 1/1893 Dormitzer 182161 579,328 3/1897 McConnell 182-161 806,915 12/1905 Reed 182-161 1,488,624 4/1924 Sperl 18296 3,012,633 12/1961 Magee 182-96 REINALDO P. MACHADO, Primary Examiner.

Claims (1)

1. IN A SAFETY LADDER STRUCTURE COMPRISING A PAIR OF OPPOSED, LONGITUDINAL, SUPPORTING MEMBERS, A SET OF MOVABLE STEPS IN SAID PAIR OF MEMBERS, A LINKAGE OPERATIVELY CONNECTED TO THE MOVABLE STEPS TO PROVIDE FOR MOVEMENT OF THE LATTER BETWEEN USABLE AND INOPERATIVE POSITIONS, LOCKING MEANS CONNECTED TO SAID LINKAGE TO LOCK SAID STEPS IN INOPERATIVE POSITION, AND MEANS MANUALLY ACTUATED TO SIMULTANEOUSLY RELEASE THE LOCKING MEANS AND OPERATE SAID LINKAGE TO PLACE THE STEPS IN OPERATIVE POSITION.

Images