US3258085A

US3258085A - Readily adjustable elongated support structure

Info

Publication number: US3258085A
Application number: US350477A
Authority: US
Inventors: Everett B Mccarty
Original assignee: MCCARTY ENTPR
Current assignee: MCCARTY ENTERPRISES; MCCARTY ENTPR
Priority date: 1964-03-09
Filing date: 1964-03-09
Publication date: 1966-06-28
Anticipated expiration: 1983-06-28

Description

June 28, 1966 E. B. MccAR-rY READILY ADJUSTABLE ELONGATED SUPPORT STRUCTURE Filed March 9. 1964 1 l l l l I J 5 Sheets-Sheet l READILY ADJUSTABLE ELONGATED SUPPORT STRUCTURE 5 Sheets-Sheet 2 Filed March 9, 1964 FIG.7

FIG. 3

June 28, 1966 E. B. MccAR-rv READILY ADJUSTABLE ELONGATED SUPPORT STRUCTURE United States Patent O 3,258,085 READILY ADIUSTABLE ELONGATED SUPPUR'I STRUCTURE Everett E. McCarty, McCarty Enterprises, 2906 1E. Broadway, Alton, Ill. Filed Mar. 9, 1964, Ser. No. 350,477 6 Claims. (Cl. 182--202) The invention involves the ready adjustment of an elongated strut-like structure such, for example, as a ladder leg, a scaffold upright, a shore or support for machinery, a building or the like.

Among the objects of the invention are to expedite the adjustment of the elongated structure, the firm securing of its parts in adjusted position, adaptation of adjustment for any variation in its length irrespective of spaced ratchet teeth or other spa-ced apart elements, the avoidance of the insecurity of loose parts or gravity actuation of latches, etc. and the automatic return of the parts to a normal or initial relation.

The invention comprises two telescopingly .assembled members, interconnected by a flexible tie snubbed around at least one grab block and automatically maintained in frictional gripping contact with the block, but readily released manually for adjustment.

In the accompanying drawings the invention is illustrated in a specific adaptation for ladders or the like, but one form is also shown which has multifarious areas of service. In these drawings:

FIG. 1 is a front elevation of a ladder, parts of the ladder being sectioned.

FIG. 2 is a side elevation of the ladder.

FIG. 3 is a vertical transverse section on line 3 3 of FIG. 1 through the lowermost step of the ladder.

FIG. 4 is a horizontal section on lin'e 4-4 of FIG. 1 through the step.

FIG. 5 is an elevation and section similar to FIG. 1 but illustrating a different form of the invention.

FIG. 6 is a side view of a structure showing another form of the invention.

FIG. 7 is a horizontal section on line 77 of FIG. 6.

The structure shown in FIGS. 14 consists of a structure applied to the lower ends of th'e legs of an ordinary wooden ladder L but may form the lower portion of a complete ladder or ladder section. It comprises two main upright channel shaped leg sections 1, 2 with telescoping

lower extensions

3, 4 projecting downwardly from the legs terminating in shoes 5, 6 pivoted to the lower ends of the extensions, each having a corrugated foot 7.

A transverse step 9 has its ends xed to the lower portions of main legs 1, 2 and is of inverted channel cross section (FIG. 3) with vertical plates 1t) depending from its flanges and cooperating with the channel section to form a deep housing enclosing drag blocks 11 at opposite ends of the housing. Each drag block has ay semicylindrical surface projecting into the

adjacent leg

3, 4. One or more additional steps 12 `are secured to legs 1, 2 as may be required according to the length of the legs.

Elongated

coil springs

13, 14 are housed in legs 1, 2 and their

extensions

3, 4. The upper end of each spring is anchored to one of the legs at 15 well above the level of lstep 9 and the lower end of each spring is anchored t0 one of the extensions at 16. The springs are elongated so that they tend to pull

extensions

3, 4 upwardly in the legs.

A flexible tie 19 such as a cable, chain or rope has its intermediate part 20 passed around drag blocks 11 to form on'e or more complete loops about the blocks. The ends of the tie are secured to

extensions

3, 4 near the upper ends of the latter and the tie is drawn taut by the tension of

springs

13, 14 until the tie loops fricice tionally grip the drag blocks 11 and thereby snub the springs and leg extensions so as to securely hold the latter against movement in their respective legs.

Mounted on the lower end 'of each

extension

3, 4 is a

transverse pin

22, 23 by which the extension (for example, extension 4) may be moved manually to the broken line position of FIG. 1, stretching the corresponding coil spring 14 and providing slack in the corresponding end portion of the tie 19. The prompt automatic contraction of the `other coil spring 13 takes up the slack in the tie and simultaneously rais'es the other extension 3.

When manual pressure on pin 23 is relieved spring 14 immediately functions with the other spring to tightly snub tie loops 20 about the grab blocks 11, securely holding the extensions in the adjusted positions, thus adapting the ladder for the uneven support surface on which it may stand.

If the ladder is moved to a more nearly level surface, the user merely steps on the other pin 22 until its foot 7 contacts the support surface, and the previously d'escribed operation is reversed. Each movement of either extension in either direction is accompanied by a corresponding movement of the other extension in the 0pposite direction and whenever the operation terminates the extensions are, in effect, Ilocked until the spring tension on the tie is removed.

FIG. 5 shows another arrangement in which the main legs 21, 32 are extended upwardly and constitute the sides of the complete ladder rather than being applied to the lower end of an ordinary ladder as in FIGS. 1, 2.

Extensions

33, 34 Icorrespond to the extensions previously described and are similarly slidable in

legs

31, 32. A transverse lower step 39 connects the legs and forms a housing for drag blocks 40, and a tie 41 is looped about the drag blocks and extends from the latter upwardly through the hollow extensions and is anchored to the latter at 42.

Aside from the greater length of the side legs the main difference between the two forms lies in the different location of the

coil springs

43, 44 which are disposed wholly above the extensions, the lower ends of the springs being attached to upper ends of the extensions and the upper ends of the springs being attached to the legs at a higher level than shown in FIGS. 1, 2, as indicated at 45.

FIGS. 6, 7 show a form of the invention embodied in a single unit which might comprise a ladder leg, a support leg or brace for any other equipment. The main member is telescoped with a lower extension 51 having a ange 52 at its lower end forming a foot on which the user may step or which may be :otherwise engaged while the unit is elongated or shortened. The lower end of an elongated coil tension spring 53 1s secured at 54 to the lower end of the extension and the upper end of the spring is secured at 55 to clip 61 on member 5t) thus exerting an upward thrust on extension 51.

The drag block 58 is fixed to the upper end of extension 51 and comprises a cylindrical drum. The tie 59 has its intermediate portion 'looped laround block 58 and has one end anchored at 60 to clip 61 on member 50 and has its other end secured at 62 t0 the upper end of another coil tension spring 63 the lower end of which is secured at 65 to the lower end of extension S1.

If member 50 is held against movement while flange 52 is stepped upon or extension 51 otherwise moved outwardly of member 50, or vice versa, the grip of the tie on block 58 is slackened and the coils 0f the tie will slip on the block periphery until the pullout movement ceases whereupon spring 63 immediately tightens the tie to grip the block and hold member 50 and extension 5l in adjusted position.

A finger piece 67 is attached to the upper end of spring 63. When the parts are extended and flange 52 held stationary and finger piece 67 pulled to elongate spring 63, the resulting slack in the tie permits the tie coils to slip on block 58 whereupon spring 53 telescopes member 50 and extension 51 until the pull on the finger piece is released or flange 52 engages the lower end of member 50. Release of the finger piece automatically tightens the tie coils about the block and the parts are held in adjusted position.

Member Sfl may constitute an entire ladder leg or may be bolted to a ladder leg G, as indicated in FIG. 6, or to any other object to be supported by the unit Si), Si or the unit may be used as a strut. The unit may be used as one of a pair or larger group of supports and if used as a ladder leg, the other leg of the ladder may be a similar unit or may be an ordinary leg.

In each form of the invention the friction between the tie and the drag lock or blocks easily holds the legs and extensions in adjusted position irrespective of any load for which the structure is adapted. The greater the load the greater the pull on the tie and the stronger is snubbing grip on the drag block or blocks. The springs do not directly carry any part of the load but merely take up slack in the tie to maintain its tight snubbing contact with the friction surface.

Preferably the telescoping members are of channel-like cross section and enclose the movable springs, tie and drag blocks, but this iis not essential as the springs and tie could be positioned outwardly of the telescoping elements as would be required if they were of bar or similar section.

The details of the structure may be varied substantially without departing from the spirit of the invention and the exclusive use of those modifications coming within the scope of the claims is contemplated.

What is claimed is:

1. In a ladder structure including upright side legs in fixed relation to each other, a drag block fixed on said structure, an extension slidable lengthwise of said structure and projecting downwardly therefrom, a spring anchored to said structure and connected to said extension and urging the latter upwardly along said leg structure, an elongated flexible tie with an intermediate portion looped about said drag block, and having an end portion connected direct to said extension and spring means having spaced portions secured to the opposite end of said tie and to said structure respectively and tensed between its ends, said tie, spring means and drag block comprising a snubbing device normally firmly holding said extension against movement relative to said leg structure, and manually operable means for releasing said snubbing device.

2. In a ladder, transversely spaced legs each including an upper section and a lower section in telescoping relation, a cross member between said legs with its ends fixed respectively to one section of one leg and to the corresponding section of the other leg and provided with a drag block, an elongated flexible tie having an intermediate portion forming a loop surrounding said drag block and having end portions secured respectively to the other leg sections at points spaced from said cross member, yielding devices each having connections at its opposite ends to the end portions of the tie and the first-mentioned leg sections and taking up slack in said tie to frictionally grip the drag block solely by the weight of said upper sections and thereby hold the sections against relative movement and manually operable means for releasing said tie from the pull of said yielding devices.

3. In a ladder, transversely spaced legs each comprising a main section and a relative short lower section telescopingly assembled with the main section, a cross member secured to corresponding sections of the legs near the lower end of the ladder, an elongated coil spring housed in each leg and secured at its opposite ends to the two sections of that leg, and urging the sections to- Ward each other, an elongated flexible tie element secured at its opposite ends reespectively to corresponding sections of the two legs and intermediate its ends normally having frictional snubbing grip on said cross member, a manually engageable element on each lower section whereby the latter may be moved downwardly to elongate one of said springs and thereby automatically release the snubbing grip of said flexible tie on said cross member while the other lower section is moved upwardly by the other spring relative to its associated upper section.

4. In a ladder, transversely spaced hollow legs, individual extensions slidable lengthwise of the lower portion of said legs and projecting below the latter, a cross member fixed at its opposite ends to the lower portions of said legs and having rigid parts with wide friction surfaces projecting from said cross member into said legs, a flexible tie having a middle portion passing around said parts and over said surfaces and having end portions extending from the ends of said member lengthwise of said legs and anchored to said extension, an elongated coil spring in each leg with its lower end secured to the lower end of the associated extension, the upper end of the spring being secured to the leg at a point spaced above said extension and normally holding the tie taut and frictionally gripping said surfaces, a manually engageable element projecting laterally from the lower end of each extension whereby downward pressure on the element will elongate the corresponding spring to temporarily release the tie from the tension of that spring and from frictional grip on said surfaces and facilitate relative movements of said extensions in opposite directions in said legs.

5. In a ladder, transversely spaced legs, an elongated extension slidable in each leg and projecting below the lower end of the leg, a transverse step fixed at its opposite ends to said legs above the lower ends thereof, said step including friction block structure, a flexible tie having an intermediate part extending around said block structure and having end parts extending along said legs, and individual devices each operatively connecting an opposite end of the tie to a respective one of the legs at a point spaced from said step, said devices including yielding means normally holding the tie taut in frictional gripping contact with said block structure and thereby firmly positioning the lower end of the extensions relative to the respective legs.

6. In a ladder, transversely spaced legs, elongated extensions slidable in each leg and projecting below the lower end thereof, a transverse step fixed at its opposite ends to said legs and spaced above the lower ends thereof, a drag block fixed to each end of said step with a semicylindrical surface facing the adjacent leg, a flexible tie having an intermediate part forming a plurality of loops around said blocks and extending upwardly therefrom and connected at their ends to the upper ends of said extensions, elongated coil springs secured at their lower ends to the upper end of said extensions and extending upwardly therefrom and secured at their upper ends to said legs, and a step member at the lower end of at least one of said extensions whereby the corresponding spring may be elongated manually to release its tension on said tie.

References Cited by the Examiner UNITED STATES PATENTS 2,330,825 10/1943 Hoit 182-202 2,366,829 l/l945 Biery 182-202 2,885,133 5/1959 Nelson 182-200 X 2,890,824 6/1959 Derby 182-202 2,914,135 ll/l959 Crouch 182-201 3,173,512 3/1965 Sturdy 182--202 HARRISON R. MOSELEY, Primary Examiner.

REINALDO P. MACHADO, Examiner.