US2848282A - Ladder platform - Google Patents

Description

Aug. 19, 1958 w. M. WEBER LADDER PLATFORM 2 Sheets-Sheet 1 Filed Nov. 30, 1955 llll Aug. 19, 1958 w. M. WEBER LADDER PLATFORM 2 Sheets-Sheet 2 Filed Nov. 30, 1955 United States Patent() LADDER ILA'IFORMk William M.' Weber, Berkeley Heights; NJ.

Application .November 30, 1955, Serial No. 549,943

1 Claim; (Cl. 304-31.5)

The invention relates in general to supports for painters, carpenters,bricklayers,-a.ud"other artisans, while working on' elevated "exteriorareas of the Wallsor chimneysofl buildings, and has parti'cularreference to aportable bracket-typeV platform.. adaptedto be mounted on a ladder of conventional construction thatis laid upon the roof` of a lower part of a-buildingfor-use as a platform'to support another ladder whichrisesttherefrom'to permit the workman to reach a so-called blind`spot""on aA higher part of the building.

It may be explained that a blind' spot? is anelevated area of the building structure which cannot bereached by a ladder standing on the -ground nor by a single 'ladder erected upon the roof offsomelower part 'of the-building dueto'the lack ofa'safey rest-ing place Lfor thelbaser'end of fthe ladder.V

Prior-*to my present invention, there vbeen no supporting 4'deviceavailable for theintended purposev thatis sufficientlyV light-in weight to 4`be operablein use 'by one man.` Although I am' aware ofone ladder platform in the priorart, that particular device' ncludeslong, heavy baseimembers thathave `to bemounted upon the supportingroof-laid-ladder and other massive parts which add prohibitively tothe Weight. The `supports for workmen 'heretofore ygenerally used are scaffolds "that require twomen toassemble them on4 the building, tol shiftV them when necessary, and to take them'down afterwards.

Itv therefore is the primaryvobjectof `niyinvention'to provide a ladder-'supported platform for'thesupportoffa second ladder, whichbracket is'of `such lightweight and simpl'econstruction that onev man-can perfornr very easily all-ofthe manual operations involvedin its'fuse'to'includey carryingit up to the'roofuponwhi'chpthe supporting ladder is laid.

A further object Vof the invention is to "provide" aladder platform of'such construction' that it'mayj vbe' erected upon `the rungsof a primary vroof-laidsupporti'ng 'ladder in 4an instant of time kand 'without' the employment of any accessory hand tools.

Otherobjects; features andadvanta'ges 'of' the invention will become apparent v asthe following specific description'is `read in connectioni with ".the accompanying, drawings,` in which:

Fig; l`is `a fragmentary side.elevationa1 view of 5a house, illustrating the operationaluse of 'the invention, wherein the ladder platform is supported by aV primary ladder lid"uponthe roofof Yan extensionofthe house and in its turn'supports'a secondary ladder, the accessory ladders being represented in broken lines.

Fig.; 2 lisl `a large-scale-"detailrplanview of 'the'- ladder platform in kladder-'attached` conditions;

Fig13 isv a sideelevationcf the samer Fig:V 4 is 'a' frontelevation;

Fig.'l 5 isa verticalsectionon-line'S-i-S of Fig.' 3j i Figa-j 6 is a' fragmentary, larger scale verticalvk section' on line 6--6 lof Figi 4; "and" l Fig.17 is'aview"'sirnilar'to"Fig; 6, sh'owingijwhath'appens whenla rungof -the primary supporting ladder' fails.

Referring nowindetail tothe drawings, wherein like reference characters designate corresponding parts in the severalevie'ws, Fig: l discloses'eth'ermanner inwhich mypreciated when it is stated that it comprises only four essential elements, viz: platform 20, a pair of struts 2'1--21, andi-means, which will be numeri'cally'designated later herein, to connect the'upper end portionsof' the struts adjustably to the'platform. The weightof the complete unit is only eighteenpounds.

Platform 20 mightconsist entirely, of a particularly ,wide piecepfchannel iron, but itis preferred to rest the lowerends of'theside bars ofV a supported secondary ladder L on awo'odensurface insteadof a metallic surfa`ce, which" latter wouldv not oifer as much frictional resistance to slipping `as wood, so'I use a board 22, which may be composed of plywood, having attached angle irons V23---23 of L-shaped cross-section extending along its under face in contiguous 'relation to the side edges thereof for a purposeto be'described presently. The combined board`22 .and angle'ironsZS-ZS thus form a horizontally wide channel construction.

At one end Vof platform Z0, which will betermed its ladder-attachment. end to distinguishfrom the opposite distal end,.downwardly opening laterally registering hinge recesses` 24'-24 are provided' independing llanges 25-25 of angle irons 23'-23 These hinge.. recesses 214-24 are intended to engage an upper rung R of 'primary ladder L andpreferably are marginally rounded 'for even bearingcontact withsaid vrung in a manner to mount platform 20 on a hinged joint, which willA permit said platform to be swung freely upward or downward into level position. The. depth of each hinge recess should ybe lsuch that its inner margin will be substantially ush with theplane of the bottom face of the horizontal base ange of the corresponding angleiron 23. Due to this. structural feature, thebase flanges of both angle irons 23`23 will bear directly upon the ladder. rung and thereby present a bearing4 contact .ofdesir'able area. In order toiinsure against accidental disengagement of 'hinge recesses 24-24 from upper rungl R, suitable clamping meansis provided. This clampingmeans'may` be of any desired construction, but it is preferred to employ a J- shaped bolt 26 asclamping=means. This clamping bolt 26 includes av hook portion 27'for pivotal .confining yengagement with upper rungR of ladder L and afstraight stem,. or shank, 28` to penetrate a centrally locatedhole 29 provided in the ladder-attachment end of platform. 20. By` threading'a wing nut 30 onto the upwardly protruding end ofstem 2S of'clamping bolt 26, the marginal edges ofrecesses 24-24 and the under faces of the horizontal base angesof angle irons 23.-23rmay4 be drawn into secure engagement with vthe ladder rung.,

Plural adjustment recesses.. 31 are formed'iri` laterally registering. pairs .in .depending vertical, flanges 25j-25A .of platform. angle irons 2li-23. A-.suitable number of these-.pairs of adjustmentrecesses Slextend longitudinally inwardly from the.distal'.end fof platform 20 ,inpreferably uniformly spaced-relation.v

The-.struts 21-21 that,are,. to supportfthe..distal..end portion'of platform 20 upon. aselected lower.rung.-Rof

lprimary ladder L.preferablyare.of. angle-ironconstruction like angle-irons 23-23.and.are. provided. with feet 32-32 -that preferably toe. vinward l in l lateral 1 alignment. Each. foot '32 preferably has a. hee1-cleat33.and a. toe cleat 34 respectively provided with downwardly-'opening hinge-recesses 35fand36-of1marginally rounded for-m.V to pivotallyl engagey ther selected ladderrtrung.. Eachfoot 3'2Ymfay `haver-its-toe'rigidlyfreinforced by being connected to its corresponding strut 21 by a diagonal brace bar 37.

Each strut 21 is provided with a longitudinal row of preferably uniformly spaced bolt holes 38 in those flanges thereof which are arranged' parallel to anges 25-25 of platform 20. Bolt holes 38 are located so that they will be in horizontally registering pairs when strut feet 32-32 are resting upon the ladder rung. A pair of recessengaging support members 39-39, which preferably are in the form of bolts having wing nuts 40-40, are adapted to be engaged separately with selected bolt holes 38-38 in the respective struts 21--21 and thereafter to be selectively engaged with that pair of adjustment recesses 31-31 of platform 20 which will cause the latter to be supported in level position regardless of the angular slope of the roof upon which ladder L is laid.

By using bolts having wing nuts in the manufacture of clamping means 26 and support members 39-39, it is practicable for the workman to assemble, adjust, and disassemble the ladder bracket without having to use any hand tools. The advantages of this feature should be obvious.

As an alternative means for connecting struts 21-21 to flangesZS-ZS of platform 20, a row of preferably uniformly spaced adjustment bolt holes 41 have been provided in said llanges in inward prolongation of adjustment recesses 31-31. These bolt holes 41 are conveniently located for use in bolting struts 21-21 in parallel abutment against platform anges 25-25 in the inoperative condition of the unit, as when it is to occupy minimum space in a transporting vehicle, in a shop, or in a merchandising package.

The operation of the invention will now be described. After a primary supporting ladder L has been laid in a suitable location on the roof from which a secondary ladder L is to be erected in order to reach a blind spot on a higher part of a building, platform is placed with the hinge recesses 24-24 in engagement with a selected upper rung R of ladder L. Then, the distal end of platform 20 is lifted into level position, one of the struts 21 is placed against a side flange of the platform preferably in a vertical position and is arranged with its foot 32 resting upon a suitably located lower rung R of the ladder with the respective recesses 35 and 36 of its cleats 33 and 34 embracingly engaging said rung. While platform 20 and strut 21 are held together with one hand, the other hand may be used to engage a support bolt `39 with the appropriate bolt hole 38 in the strut and adjustment recess 31 in platform flange 25. After support bolt 39 has been tightened by application of wing nut 40, the other strut 21 may be erected in a similar manner. If it should he discovered that platform 20 is not perfectly level due to error in initially gauging its position, the wing nuts 48-40 of support bolts 39-39 may be loosened just enough to permit these bolts to be shifted inward or outward, as the case may be, into engagement with adjustment recesses 31-31 which will afford more precise leveling of the platform. Then, wing nuts -40 are re-tightened.

If clamping bolt 26 was not engaged with the upper rung of the ladder when the attachment-end of platform 20`was placed in position thereon, it may now be installed to secure the platform in hinged relation to the ladder.

Ladders are not all of uniform width. Therefore, whenever it becomes necessary to apply the ladder platform to an especially wide ladder, the struts 21-21 may be reversed in position to cause the feet 32-32 thereof to toe outward so as to aiord support for the struts as close as possible to the base ends of ladder rung R.

It should be apparent that my improved ladder platform is readily adaptable to the various situations encountered in actual use. Due to the length of struts 21-21 and the wide range of adjustments between the same and the distal end of platform 20, the difference in slope or pitch of the roofs on which the device may be '4 mounted does not present any problem. Moreover, the two feet of struts 21-21 may be planted upon different adjacent ladder rungs if that should be desired for any reason, such as weight distribution, particularly when it is found that a chosen rung has become broken or weakened at one end.

Fig. 7 depicts a safety feature of the invention which could prevent an accident in the event that the strutsupporting rung of the primary ladder should happen to break under the weight of the workman who is standing upon the supported secondary ladder. Due to the specific structure of feet 32--32 of struts 21-21, the cleats 33 and 34 thereof will be lowered a fraction of an inch onto the roof that supports the primary ladder. Lowering -of the distal end of platform 20 no further than that will not cause the secondary ladder to slip, but complete collapse of the device would be disastrous. Such collapse will be prevented because cleats 33 and 34 will dig into the roof shingles just enough to secure the strut feet against dangerous slipping.

It will be understood that it is intended to cover all changes and modifications of the example of the invention herein chosen for the purpose of illustration which do not constitute departures from the spirit of the invention and scope of the appended claim.

I claim:

A ladder platform adapted to be supported by the rungs of a roof-laid primary ladder for the support of a secondary ladder, said platform comprising: an elongated platform having a ladder-attachment end and a distal end, said platform being adapted to be arranged in level position with its ladder-attachment end resting upon an upper rung of the primary ladder and being of channel construction having depending flanges along the side edges thereof provided at the ladder-attachment end of the platform with laterally aligned downwardly opening recesses in said flanges to embracingly engage said upper rung of the primary ladder in the manner of a substantially ladder-wide hinge connection; the depending ilanges of the platform being provided further with plural longitudinally spaced pairs of laterally aligned downwardly presented adjustment recesses; a pair of struts adapted to be arranged side by side at said distal end of the platform in straddling and slidably overlapping relation thereto and being of sufficient length in relation to the spacing between rungs of a standard ladder that either strut of the pair will overlap the sides of the ladder platform while in level position and reach downward in vertical position to a lower rung of the primary ladder while the other strut reaches downward in obliquely inclined position to the next downwardly adjacent rung; feet provided on the lower ends of said struts and having downwardly facing recesses to embracingly engage and rest upon selected lower rungs of the primary ladder; and horizontally projecting separately vertically adjustable support members provided on the respective struts for selective engagement with the laterally aligned adjustment recesses of any pair in the platform flanges to erect the platform in level position.

References Cited in the tile of this patent UNITED STATES PATENTS 69,049 Turner Sept. 17, 1867 403,636 Btterly May 21, 1889 510,194 Sellers Dec. 5, 1893 662,566 Jones Nov. 27, 1900 743,899 Lynch Nov. 10, 1903 1,028,362 King June 4, 1912 1,142,694 Gilbert June 8, 1915 1,578,388 Bower Mar. 30, 1926 2,448,746 Sundeen Sept. 7, 1948 FOREIGN PATENTS 272,180 Switzerland Dec. 15, 1950

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