US2500333A

US2500333A - Adjustable ladder leg

Info

Publication number: US2500333A
Application number: US681670A
Authority: US
Inventors: Young Walter Scott
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-07-06
Filing date: 1946-07-06
Publication date: 1950-03-14
Anticipated expiration: 1967-03-14

Description

March 14, 1950 w 5. YOUNG 2,500,333

ADJUSTABLE LADDER LEG Filed July 6, 1946 W11. TEE Scorr .YZw/vs I NVEN TOR ATTORNEY fiatenteci Mar. 14, 19 50 UNITED STATES PATENT OFFICE ADJUSTABLE LADDER LEG Walter Scott Young, Peshastin, Wash.-

Application July 6, 1946, Serial No. 681,670

3 Claims.

This invention relates generally to an adjustable ladder and more particularly to an adjustable leg and mounting apparatus adapted to cooperate with a two-legged ladder of any type, so that the adjustable three-legged ladder thus formed will be firmly supported and maintained in a laterally virtually erect position on uneven terrain. For example, such a ladder may be used in orchards and the like for picking fruit or for various other purposes where the terrain is not level, as for example, on a hillside. In such case, the third leg may be pivoted in either or both of two directions and so oriented with respect to the terrain as to firmly support and maintain the ladder in a laterally virtually upright position.

Numerous prior art adjustable ladders have attempted to solve this problem. However, such prior art ladders have had numerous disadvantages. One of the major disadvantages of such prior art, adjustable ladder constructions has been the fact that the attachment of the adjustable leg to the ladder was such as to be incapable of properly supporting the ladder when the adjustable leg was moved laterally to any considerable degree with respect to the ladder. In other words, if such an adjustable ladder were used on a hillside and the third leg were moved laterally a considerable distance with respect to the two fixed legs of the ladder, the adjustable, third leg of the ladder would support the ladder so poorly as to make it very likely that the whole ladder would collapse and fall down if any very considerable weight were im posed thereon.

My construction solves this problem in that the adjustable third leg is so mounted with respect to the ladder as to at all times and in all positions firmly and rigidly support the ladder. My invention provides a very simple, rugged construction which is inexpensive to manufacture.

Generally speaking, my invention and construction includes a ladder of any type, generally consisting of a pair of legs and interconnecting rungs, and a stabilizing leg for the ladder. Means are provided whereby the upper end of the stabilizing leg is pivotally connected to the upper portion of the ladder, said pivotal connection including means for pivoting the stabilizing leg toward and away from the plane of the ladder and means for pivoting the stabilizing leg about an axis passing through the plane of the ladder. The leg itself may be provided with an adjustable extension, if desired. Selectively operable means carried by the stabilizing leg are provided for locking the leg in any desired pivotal position. By this construction the third or stabilizing leg may be positioned at any desired angle and thereby firmly sustain the ladder itself. By employing but a single stabilizing leg,

2 such leg may be readily inserted through branches of trees when the ladder is used for picking fruit.

It is an object of this invention to provide an adjustable leg and mounting apparatus adapted to cooperate with a two-legged ladder for firmly supporting and maintaining the ladder in a laterally virtually erect position regardless of the terrain.

It is a further object of this invention to provide an adjustable leg and mounting apparatus adapted to cooperate with a two-legged ladder of relatively simple, cheap, rugged construction and having great structural strength regardless of the position of the adjustable leg with respect to the ladder.

Other and allied objects will be apparent to those skilled in the art upon a careful examination and perusal of the specification, drawings, and appended claims.

Referring to the drawings:

Fig. 1 is a front perspective view of a ladder with the adjustable leg and mounting apparatus of my invention mounted thereon.

Fig. 2 is a rear elevation of the ladder shown in Fig. 1.

Fig. 3 is an enlarged fragmentary sectional view of the ladder taken along the plane III-III of Fig. 2 showing details of the apparatus of my invention.

Fig. 4 is an enlarged fragmentary elevation of the ladder taken along the plane IV-IV of Fig. 3 showing the details of the apparatus of my invention.

More specifically, a ladder indicated generally at l is provided with two, parallel, opposed

legs

2 and 3 between which are positioned a, plurality of spaced, parallel rungs or steps 4.

Attachment members

5 and 6, which preferably may be sheet metal or the like, are riveted, bolted, or otherwise suitably attached to the tops' of the

parallel legs

2 and 3 adjacent and beneath the top 36 of the ladder I. The

attachment members

5 and 6 extend rearwardly from the ladder and a longitudinal channel member 1, which may be made of metal or any other suitable material, and which is provided with downwardly bent lips 8 and 9 at the outer ends thereof is rotatably mounted between the outwardly extending portions of the attachment members 5 and t by bolts l0 and H, and cooperating nuts, rivets, studs, or any other suitable means for rotation or pivotal movement about an axis lying in a plane parallel to the plane of the ladder.

Fixedly attached to the downwardly bent lips 8 and 9 at opposite ends of the channel 1 are the ends of a semicircular guide member indicated generally at i2, which may be made of metal or any other suitable material. The semicircular guide member l2 includes two flanged portions virtually perpendicular to each other. One flanged portion 13 extends radially outwardly; the other flanged portion I4 is virtually perpendicular to the flange l3 and extends generally toward the front of the ladder. The flange I i is provided with spaced apertures l5.

An adjustable leg 16 provided with a suitable attachment member ll, which may be made of metal or any other suitable material, is pivotally attached to the channel member 1 within the outwardly extending edges i8 and I9 and preferably at the center thereof indicated at 28 by means of a bolt and a nut, rivet, stud, or any other suitable means.

Also mounted upon the adjustable leg It is a cooperating guide means indicated generally at 2] comprising two, spaced,

bent members

22 and 23, which may be made of metal or any other suitable material, adapted to be positioned on each side of both flanges l3 and flanges Hi of the semicircular guide member l2. The two, spaced,

parallel members

22 and 23 are fixed to the adjustable leg it by rivets 24 or any other suitable means.

The portions of the two, spaced,

parallel members

22 and 23 which are positioned on each side of the radially, outwardly extending flange is} of the semicircular guide member l2 are adapted to prevent relative movement between the adjustable leg i8 and the semicircular guide member l2 in a plane virtually transverse to the plane of said semicircular guide member l2. The portions of the two, spaced members 22 and-'23 which are positioned on each side of the other flange M of the semicircular guide-member l2 are provided with aligned apertures 25 which are spaced on opposite sides of the flange 14 which is'provided with apertures 15 therein.

A spring-biased locking means indicated generally at 26 is also mounted upon the adjustable leg 56. The spring-biased locking means-26 includes a plunger 21, which may be made of metal or any other suitable material, provided with a shoulder 23. A coil compression spring '23 is adapted to be positioned between the shoulder 28 and an outwardly extending lips 30 which is fixed to the leg I3 and in the example shown is attached to the cooperatingguide means 2!. A wire, cable or the like is fixed to the lower end of the plunger and is connected to a suitable handle 32'for actuating the plunger 21. The coil spring 29 which is compressed between the shoulder 2B and lip 30 normally urgesthe plunger 2! in an upward direction and the plunger -21 is adapted to pass through the aligned apertures 25 in the cooperating guide means 2! and any one of the apertures l5 in the flange I4 of'the semicircular guide member [2 for fixing the position of the adjustable leg It with respect to the semicircular guide member l2.

The assembly comprising the semicircular guide member I2 and the channel 1, which is fixed with respect to the semicircular guide member l2, and the adjustable leg l6, which is transversely fixed with respect to the semicircular guide member 2 by means of the cooperating guide means 2|, is pivotally movable as a unit toward and away from the plane of the ladder about pivot points indicated generally at 33 and 34, or, in other words, about an axis virtuall parallel 'to the longitudinal axes of the steps of the ladder or the top of the ladder. The adjustable leg I6 is pivotally movable in a transverse plane about the pivot point 20 (about an axis passing through the plane of the ladder) whenever the handle '32 for actuating the locking means 25 is manuall actuated so as to move the plunger 21 downwardly and disengage the plunger 21 from the apertures 15 in the semicircular guide member I2. When the desired lateral adjustment or position is reached, the handle 32 is released, thus allowing the coil spring 29 to force the plunger 2! through the aligned apertures 25 in the cooperating guide means 2| and the apertures 15 in the flange M of the semicircular guide member 12, thus preventing any further movement of the adjustable leg l6 about the pivot point 28.

Thus the adjustable leg (6 may be adjusted about two axes perpendicular with respect to each other. It can readily be seen that since the point of attachment of the channel member 7 and the semicircular guide member [2 which is fixed thereto is immediately adjacent the

legs

3 and 4 of the ladder, this construction has great structural strength.

The operation of the ladder, including the adjustable leg and mounting of my invention, may be described as follows:

If it is desired to position the ladder in a laterally virtually upright or erect position with the ladder firmly supported upon terrain or ground which is inclined, the two legs of the ladder are positioned in the desired position and the adjustable third leg is pivoted about points 34 and 35 and until the adjustable leglB is in the desired position in that plane. Then the handle 32 is actuated for releasing the locking means 26 and the adjustable leg 16 is pivoted about the pivot point 28 in the plane of the semicircular guide member [2 until the desired position of the adjustable leg i6 is reached in thatplane, the relative movement of the adjustable leg in the two planes being such as to position the ladder in the desired position, regardless of the terrain or regardless of obstacles or obstructions which may be positioned immediately behind or adjacent to the ladder. This is extremely desirable in such work as fruit picking, pruning, or the like.

It can be seen that the construction of my invention is structurally strong and well adapted to firmly support the ladder, no matter what position the adjustable leg may be in with respect to the ladder, because the mode of attachment to the ladder imparts great torsional rigidity and strength to the third leg-about its lateral pivotal mounting point when locked with respect to the semicircular guide member.

There are numerous possible modifications oi this idea. For example, the channel member I need not be a channel memberat all but may be any transverse member'pivotally mounted about an axis virtually parallel to the longitudinal centerline of the steps of the ladder or the --top of the ladder taken between thelegs thereof. The pivotal attachment of said transverse'member l to the opposed legs of the ladder may be varied in any suitable manner. 'Said transverse member may be attached to the top or steps-of the ladder adjacent the legs thereof. The attachment members 5 and G are only one of many pos sible ways of pivotally attaching the transverse member adjacent the top of the ladder. The adjustable leg 16 may be provided-withvarious types of attachments for pivotally attaching the leg 16 to the transverse member 1 or it may be pivotally attached to the transverse member '1 directly in any suitable manner. The semicircular guide member l2 which is fixed to the transverse member 1 may be of any desired cross section. For example, it may have angularly related flanges instead of virtually perpendicular flanges, or it may be of an entirely different cross section. It may be welded or otherwise suitably fixed to the ends of the transverse member 7 adjacent the ends thereof. The cooperating guide means 21 may be any suitable means adapted to engage the semicircular guide member I2 and restrict movement to the transverse plane thereof. The coopcrating guide means 25 may be dispensed. with en tirely, if so desired, and reliance placed entirely upon the locking means 26 for preventing movement of the adjustable leg 16 with respect to the semicircular guide member 1 2 in either direction. The locking means 26 may be normally springbias closed, as shown, or it may normally be open and manually, selectively closable. The locking means may take an entirely different form from that shown in the illustrations herein. Any suitable locking means adapted to selectively cooperate with and engage the semicircular guide member 12 so as to prevent movement in the plane of said semicircular guide member 12 may be used.

I claim:

1. An adjustable leg and mounting apparatus adapted to cooperate with a two-legged ladder comprising; a longitudinal channel member pivotally mounted with respect to the ladder adjacent and virtually parallel to the top and between and virtually perpendicular to the opposed legs thereof, said longitudinal channel being provided with a radially, outwardly extending, semicircular guide member havin two virtually perpendicular flanges, one of which extends radially outwardly and the other of which is provided with spaced apertures therein; an adjustable leg pivotally attached to the long tud nal channel member at the center thereof and within the outwardly extending edges of the channel so as to pivot in a plane virtually parallel to or containing said channel member; cooperating guide means mounted upon the adjustable leg comprising two, bent, spaced members adapted to be positioned on opposite s des of both perpendicular flanges of the semicircular guide member, the portion of the cooperating guide means positioned on each s de of the radially, outwardly extending flange of the semicircular guide member being adapted to prevent relative movement between the adjustable leg of the sem c rcular guide member transverse to the plane of the semicircular guide member, the portion of the cooperating guide means nositioned on each side of the other flange of the semicircular guide member being provided with ali ned apertures: and spring b ased, normally locked but manually select vely releasable. looking means mounted upon the adjustable leg and adapted to cooperate with aligned apertures in the semicircular guide member and cooperating gu de means for controlling pivotal movement of the adjustable leg about its pivotal attachment to the channel member.

2. An adjustable leg and mounting apparatus adapted to cooperate with a two-legged ladder comprising: a longitudinal channel member pivotally mounted with respect to the ladder adjacent the top and between the legs thereof so as to pivot about an axis virtually parallel to the longitudinal centerlines of the steps of the ladder and between the legs thereof, said longitudinal channel being provided with an outwardly extending, semicircular guide member having two angularly related flanges, one of which extends outwardly and the other of which is provided with. spaced apertures therein; an adjustable leg pivotally attached to the longitudinal channel member adjacent the center thereof so as to pivot in a plane virtually parallel to or containing said axis; cooperating guide means mounted upon the adjustable leg comprising two, bent, spaced members adapted to be positioned on opposite sides of both angularly related flanges of the semicircular guide member, the portion of the cooperating guide means positioned on each side of the outwardly extending flange of the semicircular guide member bein adapted to prevent relative movement between the adjustable leg of the semicircular guide member transverse to the plane of the semicircular guide member, the portion of the cooperating guide means positioned on each side of the other flange of the semicircular guide member bein provided with aligned apertures; and spring biased, normally locked but manually selectively releasable, locking means mounted upon the adjustable leg and adapted to cooperate with aligned apertures in the semicircular guide member and the cooperating guide means for controllin pivotal movement of the adjustable leg about its pivotal attachment to the channel member.

3. An adjustable leg and mounting apparatus adapted to cooperate with a two-legged ladder comprising: a longitudinal channel member pivotally mounted with respect to the ladder adjacent the top and between opposed legs thereof so as to pivot about an axis virtually in a plane parallel to or the same as the plane of the ladder and virtually parallel to the steps of the ladder, said longitudinal channel being provided with a radially, outwardly extending semicircular guide member having two virtually perpendicular flanges, one of which extends radially outwardly and the other of which is provided with spaced apertures therein; and adjustable leg pivotally attached to the longitudinal channel member at the center thereof and within the outwardly extending edges of the channel so as to pivot in a plane virtually parallel to or containing said axis; cooperating guide means mounted upon the adjustable leg adapted to cooperate with the outwardly extending flange of the semicircular guide member for preventing relative movement therebetween transverse to the plane of the semicircular guide member; and spring biased, normally locked but manually selectively releasable, looking means mounted upon the adjustable leg and adapted to cooperate with the semicircular guide member for controlling pivotal movement of the adjustable leg about its pivotal attachment to the channel member.

WALTER SCOTT YOUNG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 624,739 Beall May 9, 1899 983,172 Sheetz Jan. 31, 1911 1,087,286 Franklin Feb. 17, 1914 1,377,579 Hedden May 10, 1921' 1,471,290 Stevens Oct. 16, 1923 1,780,386 Harrison Nov. 4, 1930 1,815,316 Kingsbury July 21', 1931 1,829,980 Burgess Nov. 3, 1931