US2641401A - Ladder - Google Patents

Description

June 9, 1953 H. JAMES 2,641,401-

LADDER Filed May 15, 1950 I VEN TOR. de/sc/le/ James ZZea C. )WM

Patented June 9, 1953 UNITED STATES FAT 01? FICE LADDER Hench-eh James, Dryden. Wash.

- np ca i' nlld 50, s riat'Norlifiliwo 4 Claims;

fhis invention, relates. to a ladder and an obiect; of this invention is to provide a; ladder which is especially well adapted for orchard use but which can be used in other work.

Another object of this invention is to provide a ladder having a single medial tubular post and having an extension armslidably and telescopically disposed in said post and having endless belt type extension arm adjusting means connected with said extension arm, providing for is quick and easy adjustment of the. extension; arm between a position within the post and positions in which the arm extends above the. post.

Another object of this invention is to provide a ladder having a single medial post, provided with cross teps and having sheet metal side rail straps secured to the ends of said cross steps at both sides of the ladder. to brace and support said. steps, said straps being secured to said, post beyond the two end, steps of the ladder and; said straps having tensioning; means connected therewith and said straps having curved forward edges which extend around the. forward edges of the steps to provide fruit bag supporting, rails.

Another object of this invention is to provide a ladder having a single, medial post and having a self leveling self locking base pivotally connected with the, lower end portion of said post.

Other objects of this. invention are to provide a ladder of. strongand ruggedconstruction which is not expensive to manufacture. is; safe touse, is not heavyto handle and one on which the. user can stand on the top step and work. without danger of falling due to the provision of an ex,- tensi'on arm extending above the ladder proper.

Other objects, of thisinvention will be apparent from the following description and appended claims taken in connection; with theappended drawings which disclose preferred embodiments of the invention by way of example.

In the drawings Figure I a front elevation of a ladderconstructed in accordancewiththis invention showing an extension arm thereof in a raised orextended position.

Fig. 2 is. a sectional view taken substantially onbrokenline 2-2 of Fig. 1v and on a larger scale than. Fig. 1..

Fig. 3: isv a detached fragmentary perspective view. p rtly seetiomshowing a sheet. metal truss stri which is s cured to the ends. of the steps of the ladder.

Fig... 4 is a fragmentary sec ional: view on a larger scale. than Fi 2' taken sub tantially-on broken. line 4-4, of Fig. 2 and showing a. method of attachinga side railstrap. to. the-ends of. th ladder steps.

Fig. 51s a detached fragmentary view showing: cable means for raisingand lowering a telescopically disposed extension arm.

Fig. 5 is a fragmentary view partly in elevation and partly in section showing adjustable tensioning means for anchoring side rail straps.

7 is a fragmentary-sectional view showing alternativemeans for securing ladder steps to an angle bar.

Fig. 8 is another fragmentary view partly in plan and partly in crosssection showing a metal step welded to an angle bar post and having a tread portion of rubber or like material secured thereto.

Fig. 9 and 10 are two views partlyin cross section and partlyin plan, similar to Fig. 2, and showing two different modified forms of ladder post and. extension arm means.

Fig. 1-1 is a fragmentary View in front elevati -on showing a. pivotaljly connected self leveling self locking ladder base.

Fig. l2v is an edge view of the apparatus shown in Fig. ll.

Like reference numerals designate like parts throughout the several views.

Figs. 1 to 6 inclusive show a ladder of a type adapted to be restedon the ground and leaned against any suitable support and sometimes referred was a lean up ladder. This ladder comprises an upright tubular post l2 having a flat plate f3, Fig. l, welded or otherwise rigidly secured to. its lower end portion. An angle bar t l fits; over and receives the post 12 and is rigidly secured to said post 12 with the post parallel to the angle bar and disposed within the concave side of the angle. bar. A plurality of metal bands or straps. l5, as shown in Figs. 1 and 2, may be used to secure. the. tubular post 12 and angle bar M together or said post It and angle bar it may welded together.

A. ladder base it which is capable of self adjustment. to. conform to sloping and uneven surfaces: or side hills is n-ivotally secured, as by a pivotmember fl. to the plate l3 on the lower end portion of the tubular post: l2. If. desired the ladder base shown in Figs- 11. and 12 and herei-nafterdescribed ay be used in pl f he ladder base M5; on the ladder shown in Figs. 1 to 6..

The angle. bar Ht has. spaced apart cross steps 18., which may he of ould. ri idly secured to the apex portion thereof as: bycap screws it. Preferab y steps, 18 are,, not positioned exactly at right;- ansl s to. he angl bar M and post 12 bu are inclined slightly s ha they w ll e substantially level when the ladder is inclined 3 from the vertical at about the angle at which a ladder is ordinarily used.

I show the cap screws 19 to be threaded into a member 20 of triangular cross section which is positioned in the vertex portion of the angle bar 14 and may be welded to said angle bar 14. The member 20 can be a continuous strip of metal or it can be in the form of a plurality of nuts welded to the angle bar It. Obviously bolts 2|, Fig. 7, having tapered heads 22 thereon can be used in the angle bar It and nuts 23 can be provided on the outer ends of these bolts to hold the cross steps It thus dispensing with the member 20. Preferably washers 2 are used on the cap screws E9 and bolts 2!.

An'extension arm 25 is slidably and telescopically disposed within the tubular post 12 and can be adjusted so that it extends variable distances above the top end of said tubular post I2. This arm 25 can be placed inthe crotch of a tree or against a tree branch or against any suitable support for the purpose of holding the ladder in a generally upright position and to serve as a hand hold for the user when he is on the upper steps of the ladder.

An endless belt type cable 2% is provided for longitudinally adjusting the extension arm 25 in the tubular post E2. The cable 26 is operatively disposed on two sheaves 27 and 28 with one lap of said cable positioned within the tubular post 52 and the other lap of said cable positioned on the exterior of the tubular post I2. A turnbuckle 25. is interposed in the lap of the cable 26 which is on the outside of the tubular post [2 to provide for taking up slack in the cable 26 and to serve as a hand hold in adjusting the extension arm The sheaves 27 and 255 are rotatively mounted on the exterior of the tubular post l2 and the cable passes into and out of said post [2 through openings 3B, Fig. 5. The cable 26 is welded or otherwise fixedly attached to the lower end portion of the extension bar 25 by attachment means 3!, Fig. 5. The extension arm 25 is of a diameter sufficiently smaller than the internal diameter of the tubular post l2 to afford clearance for operation of the cable 26. The friction tending to resist movement of the arm 25 and cable 2E and sheaves 2'1 and 28 is preferably sufiicient to hold the arm 25 in an extended position when the ladder is upright but said arm 25 is easily raised or lowered by manual manipulation of said cable 25. The cross steps 18 of the ladder are trussed and supported and held rigid by metal side rail straps 32 which extend lengthwise of the ladder and are secured to the ends of the steps at both sides of the ladder. These metal side rail straps 32 converge below the lowermost cross step i 8 and are secured, as by bolt means 33 to the angle bar it. Obviously the straps 32 may be two pieces of sheet metal secured as by the bolt means 33 to the upright post structure formed by angle bar I l and tubular post I 2 or they may be in the form of a single piece of metal anchored as by the bolt means 33 to the upright post structure.

Preferably the two upper end portions of the I A bolt 37, which has a hook shaped upper end portion 38 is passed through registering holes 39 and 40 in the bent over end portion 36 of each strap 32 and in the adjacent washer plate 35 and has a nut 4| threaded onto its lower end portion. The hook shaped upper end portions 38 of the two bolts 31 are hooked over the upper end of the angle bar 30 and the nuts M are tightened thereon to evenly tension the side rail straps 32 and support the cross steps 18 at right angles to the angle bar I4.

Preferably at least the forward edge portion 42 of each side strap 32, see Fig. 3, is hemmed or reversely bent underneath the strap and the overlapping forward edge of each strap, provided by this reverse bending, is curved to fit around the corner portions of the steps, see also Fig. 2. These reversely bent forward edge portions 42 thus form smooth side rails against which a fruit picker can rest and slidably move a bag of fruit as he descends-the ladder. Obviously the rear edge portions of the straps 32 can be reversely bent and curved similarly to the front edge portions if desired.

Preferably each end of each step I8 is secured to the adjacent side strap 32 by an angle bracket 43, Fig. 4, which is attached to the side strap as by one or more rivets M and is attached to the step by at least one cross bolt 1-15 and by preferably two screws 46. The screws 48 extend through the side strap 32 and through the angle bracket Q3 and into the end of the step l8.

Fig. 8 shows a metal step A! which is secured to an upright angle bar M by weld means and which has a covering or coating d9 of tread materialsuch as rubber or plastic on its upper surface, the tread material 49 preferably having a high coefiicient of friction.

The ladder shown in Figs. 1 to 6 may be used as an ordinary lean up ladder without extending the arm 25 or said arm 25 may be extended any desired amount to reach a suitable support or to provide a convenient hand hold by which the user may balance himself when on the upper steps. Obviously this arm 25 may extend above the support against which it rests to provide a hand hold at a convenient height. This hand hold makes it safe and convenient for a person to ascend the ladder entirely to the top step and to work from the top step or steps.

The ladder structure shown in Fig. 9 is similar to the structure shown in Figs. 1 to 6 inclusive except that upright post and extension arm means of different shape and form is used. This different post and extension arm means comprises a tubular metal post 50 of substantially square cross section having a tubular metal extension arm 5| Of substantially triangular cross section slidably and telescopically disposed therein. The cross steps and cross step attaching means and side rail straps and cable and sheave devices for vertically adjusting the extension arm 5! in the Fig. 9 construction are similar to those previously described and shown in Figs. 1 to 6 and are similarly numbered. The cross steps l8 of Fig. 9 are secured to a corner portion of the square post 59. The extension arm 5| is of triangular cross section and is of the correct size to fit slidably within and occupy approximately one half of the internal space in the post 50. This leaves ample space in post 50 for operation of the extension arm adjusting cable 26 and for the member 20 into which the step securing cap screws l9 are threaded and makes it possible to provide free and easy sliding fit of the extension arm and at the same time to hold said arm 5| in accurate alignment with the post 50.

Fig. shows another modified form of upright post and extension arm for a ladder. In the Fig:

10 structure the post 52 is a cylindrical tube and cross steps l8 are secured directly to this post 52 as by cap screws 19 which thread into an upright bar 20 within the post 52. A tubular cylindrical extension arm 53 of substantially smaller diameter than the post 52 is slidably and telescopically disposed within said post and one side of the arm 53 is supported by the upright bar 20. This leaves room within the post 52 for the operation of an extension arm adjusting cable 26' similar to the previously described cable 26.

Figs. 11 and 12 show a self leveling self locking ladder base which can be used on the ladder shown in Fig. 1, or on a ladder like the ladder shown in Fig. 1 but which does not have the extension arm 25, or on a tripod type ladder which has a single supporting leg to hold it in an upright position so that it does not need to be leaned against a tree or like support. I

The ladder shown in Figs. 11 and 12 comprises an upright medial post 54 having cross steps 55 and side rail straps 56 which correspond to the parts [2, l8 and 32 of Fig. 1. A base plate 51 is pivotally secured to the post 54 by a pivot member 58 and has two divergent legs 59 rigidly secured thereto. The top edge portion of base plate 5! is curved on an are which has as its center the pivot 58 and said top edge portion has a rearwardly extending flange 60 provided with notches 6|. A latch member 62 is adapted to engage within the notches 6| to hold the base plate 51 in any position in which it is placed. The latch member 62 shown in Figs. 11 and 12 is of bell crank shape in side elevation, is fulcrumed on a pivot member 63 and has a spring 64 connected therewith to hold it in engagement with the flange 60. Preferably the latch member 62 straddles the post 54 and engages with the flange 60 in two locations at opposite sides of said post for more secure holding of the base plate 51. The latch member 62 may be pivotally moved to release the base plate 51 by exerting a pressure on a foot pedal 65 which is fulcrumed on a pivot 66 and connected with the latch member 51 by links 61.

The foregoing description and accompanying drawings disclose preferred exemplary embodiments of this invention but it will be understood that changes in the same may be made within the scope and spirit of the following claims.

I claim:

1. In a ladder a medially disposed longitudinally extending ladder supporting tubular post; cross steps rigid with and carried by said post; an extension arm slidably and telescopically supported within said post and adjustable through the top end of said post in substantial alignment with said post to any desired position within a predetermined distance above the top end of said post; and endless cable extension arm moving means connected with said extension arm.

2. In a ladder a medially disposed longitudinally extending ladder supporting tubular post;

Number cross steps rigid with and carried by said post; an extension arm slidably and telescopically supported within said post and adjustable through the top end of said post in substantial alignment With said post to any desired position within a predetermined distance above the top end of said post; two sheaves rotatively supported by said post adjacent the opposite ends of said post; and an extension arm adjusting cable extending in endless belt fashion over said two sheaves, said cable having one lap positioned within said tubular post and secured to the lower end portion of said extension arm and the other lap positioned outside of said tubular post in a readily accessible position for manual adjustment of said extension arm.

3. In a ladder a tubular post; cross steps rigid with and carried by said post; an extension arm slidably and telescopically supported within said post for projection above said post; two sheaves rotatively supported by said post adjacent the upper and lower ends respectively of said post; an extension arm adjusting cable extending in endless belt fashion over said two sheaves, said cable havin one lap positioned within said tubular post and secured to the lower end portion of said extension arm and having the other lap thereof positioned outside of said tubular post; and a turnbuckle in the outer lap of said cable providing a hand hold and cable tensioning means.

4. In a ladder, an angle bar; spaced apart ladder steps extending crosswise of said angle bar and rigidly secured to the apex portion of said angle bar; a tubular post positioned within the trough shaped side of said angle bar and rigidly secured to said angle bar; an extension arm telescopically and slidably supported by said tubular post and adapted to extend beyond the upper end of said post; and flexible endless belt type extension arm adjusting means carried by said tubular post and connected with said extension arm, whereby said extension arm can be longitudinally adjusted to any desired upwardly protruding position within a predetermined distance above the top end of said tubular post.

HERSCHEL JAMES.

References Cited in the file of this patent UNITED STATES PATENTS Name Date Cannon Nov. 16, 1880 Vieregg Aug. 26, 1890- Weiss Jan. 29, 1901 Boyd (Jet. 18, 1910 Sheetz Jan. 31, 1911 Noyes June 30, 1914 Harrison Nov. 4, 1930 Benton et al July 28, 1936 Bailey Aug. 25, 1936 McCarron July 7, 1942 FOREIGN PATENTS Country Date Great Britain Aug. 25, 1938 Number

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