US2914135A

US2914135A - Equalizing foot attachment

Info

Publication number: US2914135A
Application number: US662123A
Authority: US
Inventors: Elmer A Crouch
Original assignee: SEEGER WILLIAMS Inc
Current assignee: SEEGER WILLIAMS Inc; SEEGER-WILLIAMS Inc
Priority date: 1957-05-28
Filing date: 1957-05-28
Publication date: 1959-11-24
Anticipated expiration: 1976-11-24

Description

Nov. 24, 1959 A. CROUCH EQ UALIZING' FOOT ATTACHMENT Filed May 28, 1957 INVENTOR. Elmer A. C'rauc/r 463Y 45 M aw 197 TURNED S EQUALIZING FOOT ATTACHMENT Elmer A. Crouch, Newtown, Conn., assignor to Seeger- Williams. lnc., Bridgeport, Conn., a corporation of The present invention relates to an attachment for ladders or the like for enabling a ladder to be stable and safe when supported by its ends on uneven surfaces.

The present application is a continuation in part of my copending applications, Serial No. 393,432 and Serial No. 505,123, filed November 20, 1953, and May 2, .1955, respectively, both now abandoned.

Devices which are utilized to support persons and/or things above the ground generally have a plurality of legs whose ends rest on the ground and if they only have two legs such as a ladder, the other end of the legs rests on a structure, While with three or more legs the devices are self-supporting. In order to provide a safe and sturdy support, it is essential that the ends of the device rest on a flat horizontal surface otherwisethe device will be canted or tilted which causes it to be unstable when used. This is particularly true of ladders where the ends of the legs must be in the same horizontal plane or else the ladder becomes vertically unstable. Naturally this limits the places where a ladder may be safely utilized or, even Worse, the user is apt to provide wedges or other temporary leveling structures which, though making the ladder straight, actually may make the ladder unsafe.

Itis an object of the present invention to provide an attachment for the legs of devices such as ladders which enable them to be safely used on uneven surfaces such as sloping ground, stairs, etc.

Another object of the present. invention is to provide an attachment as above set forth which isquickly and easily adjusted to provide a leveling of the ladder and which may be locked in such a position when in use.

A further object of the present invention is to provide a ladder attachment of the above mentioned type in which the attachment may be positively locked in the desired position and yet the positive or safety locking element is unobvious and difficult to accidently manipulate.

Another object of the present invention is to provide an improved equalizing foot attachment as set forth above which is simple and economical in construction, strong and sturdy, and reliable in operation.

In attaining the above objects the equalizing foot attachment of the present invention comprises a foot which is attached to the end portion of a leg of a ladder and is movable with respect to the ladder thereby constituting in effect a ladder leg adjustable in length. The foot is,

attached to a rod which is axially movable in a base and the latter is fastened to the end portion of the leg of the ladder to extend therebeyond. The rod and foot are freely movable in an extending direction but are automatically locked to the base upon movement in a reverse direction. Releasing means are provided to enable retraction of the foot after use which consists only of a movable shaft.

A feature of the present invention resides in a safety lock to prevent movement of the shaft and hence unlocking of the rod and this consists of a rotatable abut ment threaded onto the shaft to be adjusted to prevent any releasing movement of the shaft. -Upon release of the lock, after use, a spring causes retraction of the foot 2,914,135 Patented Nov. 24, 1959 ice to its rest position. Thus, merely holding the ladder in place, extending the foot, if desired, by stepping on it, is all that is needed to provide a safe and sturdy support, for

a ladder on uneven ground and to prevent the retractionof the foot, either accidently or through mischief, the safety lock is rotated to prevent release of the foot lock. The equalized foot attachment of the present invention accordingly acts as a stepless adjustable extension for the end of the ladder leg.

Other features and advantages will hereinafter appear.

In the drawing:

Figure 1 is an elevation of the end portion of a ladder with each leg being provided with an equalizing foot attachment of the present invention.

Fig. 2 is a section of the attachment of the present invention shown at its retracted or rest position.

Fig. 3 is a detail sectional view of the safety lock for the releasing mechanism.

Fig. 4 is a section taken on the line 44 of Fig. 2.

Fig. 5 is a section taken .on the line 55 of Fig. 2.

Fig. 6 is an enlarged section of the foot locking mechanism.

Fig. 7 is a detail view of an element of the attachment.

Referring to the drawing, there is shown in Figure 1, a ladder 10 having rungs .11 and legs 12. While a ladder is shown and specifically referred to in the description of the equalizing foot attachment of the present invention, the attachment is usable with other support devices having legs such as portable staging, etc. Attached to the lower end portions of each leg 12 of the ladder are equalizing foot attachments generally indicated by the reference numeral 12. Though an attachment is shown for each leg, it will be apparent that only one attachment is required for the ladder. The ladder 10 is shown being maintained vertically upright even on a sloping surface 14 by one attachment being extended to engage the lower part of the sloping ground to cause the ends of the ladder legs to be in the same horizontal plane. Though the ladder is shown specifically as being used on slopping ground, it will be apparent that it may also be used on stairs and other uneven surfaces where the two ends of the ladder legs cannot, by resting on the surface without the attachment, be located in the same horizontal plane.

The attachment 13 includes a base 15 having a side portion 16 with three integral spaced flanges, an upper 17, an

intermediate 18 and a lower 19, extending perpendicularly from the side portion 16. The lower two

flanges

18 and 19 each have an aperture 20 and 21 respectively formed therein which are aligned and constitute a bearing surface for a hollow rod 22 which is positioned therein and movable with respect thereto. The rod 22 has attached to its lower end a foot 23 which is the part of the attachment which engages the ground. The upper flange 17 has a pin 24 which holds one end of a spring 25 and the spring extends through the rod and its other end is fastened thereto by a diametric pin 26 at the foot end of the rod. The spring is under tension and urges the rod to its retracted or rest position shown in Fig. 2 in which the rod engages a resilient bumper 27. Snapped into a groove 22a formed in the upper end portion of the rod 22 is a rubber O-ring 22b which engages the flange 18 to preof the plates have holes 32a through which a shaft 33 passes. A clip 34 fastens the plates to the shaft so that movement of the shaft causes pivoting of the plates. The shaft 33 is biased upwardly by a spring 35 circumscribing its upper end portion which causes an upward canting or tilting of the locking plates with respect to the axis of the rod with the result that a positive lock between the rod and plates is automatically caused and maintained. Accordingly, with the above construction, a force exerted axially on the rod to extend it encounters no opposition from the locking plates and this may easily be done merely by stepping on the foot 23 while adjusting or holding the ladder in its vertical position. The locking plates prevent any retraction of the rod and lock the rod in the desired extended position by the edges of the apertures of the plates engaging the surface of the rod as shown in Fig. 6.

In order to release the lock between the plates 28 and rod 22 there is provided a releasing mechanism which upon actuation renders ineffective the lock and permits the spring 25 to return the rod and foot to their retracted or rest position. In the specific embodiment shown, this mechanism comprises a manually operable knob 36 fastened to the upper end of the shaft 33 which upon downward movement of it and the shaft against the force of the spring 35 causes the locking plates to be moved to a substantially diametric or perpendicular position with respect to the rod (as indicated in dotted lines, Fig. 6), thus the lock is released. The shaft 33 is slidably mounted in a tube 37 which is connected to the flange 18 by a hollow bolt 38 threading into the tube. The upper end of the tube 37 is provided witha hollow enlarged head 39 which rests on the upper flange 17 and in which the spring 35 is contained. The upper end of the shaft 33 has .a threaded portion 40 on which is threaded a flanged nut 41. The nut is freely movable into the enlarged head 39 of the tube and by threading the nut clockwise, the nut advances on the shaft 33 and into the tube until its flange engages the head 39 of the tube. In this position, shown in Fig. 3, the shaft 33 cannot be moved downward in the tube. The flange of the nut 41 and the end of the tube constitute the safety lock for the releasing mechanism. It will be appreciated that the safety lock is easily rendered effective simply by turning of the nut 41 which may 'be knurled to facilitate manual manipulation. It will further be appreciated that the construction of the safety locking mechanism enables quick locking or unlocking and yet 'once locked it provides a positive prevention of operation of the releasing mechanism. In addition, the safety lock is not susceptible to accidental operation and moreover its operation is not obvious, for example to a child, who may out of curiosity attempt to release the look.

In order to provide for substantially limitless usage of the attachment, the foot 23 is mounted for universal movement at the end of the rod 22. To this end, the foot, as shown comprises a fiat plate 42 having a corrugated resilient pad 43 and a pair of upstanding ribs 44. The ribs have an aperture 45 through which a pin 46 .passes to fasten the plate for pivotal movement about the pin 46 to a plug 47. A cotter'pin 48 may be utilized to maintain the pin in place. The plug has a circular reduced end 49 which is received within the end portion of the rod 22 and is formed with an annular groove 50 therein. Fitted within the groove is the central portion of a pin 51 which is secured chordally in the rod end portion. Thus, the plug is secured to the rod and yet the plug may be rotated with respect thereto. Accordingly, the footmay be rotated and pivoted and hencehave a substantially universal movement in order to accommodate itself to variations in the slope of the surfaces.

The pm 46 is shown in detail in Fig. 7 and is composed of an end portion 46a offset from an intermediate portion 4612 located between the offset portion and an.aperture 460 for the cotter pin and the other end portion 46d. In use, the

end portions

46a and 46d extend beyond the r1bs 44, and thus provide a surface which may be stepped 4 on to cause extension of the rod 22. Thus the users hands are not required to extend the attachment to the position necessary to maintain the ladder vertically stable.

It is presently preferred to releasably fasten the attachment to the ladder leg. To this end, the side portion 16 of the base is formed with two keyhole slots 52 while fastened to the ladder are two cooperating headed lugs 53. Thus the attachment may be securedto the ladder by passing the heads of the lugs through the larger portion of the keyhole slots 52 and moving the attachment upward with respect to the ladder so that shanks of the lugs are in the small portion of the slots while the head is on the outside side of the base, as shown in Fig. 1.

It will thus be appreciated that there has been disclosed an equalizing foot attachment which provides a reliable and sturdy support enabling the safe use of a ladder on uneven surfaces. The attachment has a foot which is adjustable in length and in effect constitutes an adjustable extension of the ladder leg with the extension being substantially steplessly adjusted and automatically locked in any desired position. A simple manual push on a shaft serves to release the lock and a spring causes the foot to snap back to its retracted or rest position. Moreover, according to the present invention, there is a simple yet extremely effective safety lock for the releasing mechanism which is incapable of being accidently operated and in addition is not apt to be operated mischievously.

Variations and modifications may be made within the scope of the claims and portions of the improvements may be used without others.

I claim:

An adjustable equalizing supporting attachment for a ladder having a leg comprising an elongate base having a plurality of spaced flanges, said base being formed with slots adapted to provide a removable attachment to with respect to the rod for creating a frictional lock therebetween and movement of the shaft in a direction againstthe urging of the spring for releasing the lock; a nut threaded on the shaft for movement therewith; an abutment mounted on a third flange and engaged by the nut for limiting movement of the shaft, said nut normally permitting movement of the shaft but being threadable to a position to prevent movement of the shaft and hence unlocking of the frictional look; a spring connected to the rod and normally urging the rod to a retracted position, whereby said rod upon being unlocked automatically retracts; a plug mounted in the lower end of the rod and having an annular groove;.a pin extending chordally of the rod and passing through the groove to retain the plug in the rod yet permit rotation thereof; and a foot having a flat ground-engaging portion and a pivotal connection to the plug, whereby the foot is rotatable and pivotable with respect to the base.

, vReferencesCited in the file of this patent UNITED STATES PATENTS 7,561 I-Iull Mar. 20, 1877 938,114 Boettcher Oct. 26, 1909 1,177,069 Souccie Mar. 28, 1916 2,147,052 Noone Feb. 14, 1939 2,313,469 .Forsman Mar. 9, 1943 .2,495,674 Lewis ,Jan. 24,1950 2,555,036 Husted May. 29, 1951 2,603,515 Thomas July 15,1952 2,815,130 Franks Dec. 3, 1957