US1921583A

US1921583A - Ladder construction

Info

Publication number: US1921583A
Application number: US568225A
Authority: US
Inventors: Reed George Berkeley
Original assignee: METROPOLITAN DEVICE CORP
Current assignee: METROPOLITAN DEVICE Corp
Priority date: 1931-10-12
Filing date: 1931-10-12
Publication date: 1933-08-08
Anticipated expiration: 1950-08-08

Description

Al1g- 8, 1933- G. B, REED LADDER CONSTRUCTION Filed Oct. l2, 1931 2 Sheets-Sheet l a Z LM* QYu Z. Z ZM W J 7, Av7a 0 m a .ad /4 y 6W 2 MK n .y MW o0 6 6 FW. f .TA ifa F @Y 5B. d G o W o w @i l w ww ad Aug. s, '1933. G, B. REED 1,921,583

LADDER CONSTRUCTION Filed Oct. 12, 1951 2 SheetS-Sheei 2 YT @W l N V E N T o R GEO@ @s55/Wma. .5H/'5550.

ATTORN EY.S

Patented Aug. 8,1933 l e UNITED. STATES 1li/irrt1511i OFFICE] LADDER CONSTRUCTION j George Berkeley Reed, New York, N. Y., assignorl v to Metropolitan Device Corporation, Brooklyn, N. Y., a Corporation of New York .Application octoberiz, 1931. serial No.[5ss,22`5

i 7 claims. (01.,228-6) e l invention relates ladder construction means is notfshow'n it forms -nopart' ofthe and while notlimited thereto is particularly present invention. A adapted for use in connection with portable lad- When the ladder iSl1r&I1SD01td, it. isteferably ders such as those mounted on `automobiles or disposed in a horizontal position. For so holding 5` similar-vehicles. -The 4inventionaims to provide the ladder, in this position,.I `provideapableV32, Y

means for holding the ladder somewhat rigidly One end of vwhich is securedto a ttng V34: faS-y in a f-substantially horizontal position during tepedieal" the base end of themain lladder seetransportation. t Other features of the invention tion` 10. vThe other end of tlfiecablejsv securedv relate` to the provision of Wide steps carriedl by;` tOanlIeboltlSG carried by the framegl.'V

10A the rungs of the ladder and also to safety means# 2 The pvOtal SUDDOIU 14 0f the mainv ladder lie-[6&5 which enable a Workman to work. freely withrboth ingk located olf center -with respectfto the length V hands without fearof losing his balance. f Y thereof,- lt Will be. understood that, the'geatr The above and other more detailed'eatures of; Weight` 0f the lOnger'lJalt theleOf Oli One Side 0f the invention Will be fully apparent from the'fol the pivot will tendv to ,Swing ym6101518 "end dOWn- ,l l5 lowing specification when read in connectionwith ward.' The `cable 32 ofr course'islof such length the accompanying drawings ,andfwillbe dened so as to normally hold the A4ladderfin a substanf, with particularity in the appended claims. Y tially-horizontal position las illustrated in dotted In the drawingsg- Y 1 j I lines `in Fig. 1 and full linesin Fig. 6. With'suchy Fig. 1 is a side elevation showingin fu1l-lines an ,'arrangement, it Vwill be understood therefore .20 an extension ladder in Working position embodythat the ladder vis supported Afor transport by 75 Y 25, extension portion of the nader;

ing my invention, the view also shows a ladder means extraneous, or independent ofthe .vautocollapsed, in broken linesfin the position for mobile structure. ThisV is desirable for anyauxtransportation; iliarygsupports secured'to thegframe or bodyof the l 2 is an enlarged detail vView of the upper automobile are vaptV to move relatively tothe Y iframe. Such relative -movement orswaying` of Fig. 3 is a horizontal section on line 3--3 of the automobile frameV relativelyjto the ladder Fig. 2;V t supporting frame willgcause annoying yrattles or Fig. 4 is av detail view of a notched bracket noises. `Alsoif part ofthe ladder rests onA a sup-` shown at'the upper part of Fig;V 2; ,i port carried by the frame a jogging causes -Wear 30 Fig. 5 is a detail view on line 5-5 of Fig. 2; on the ladder aswell as the support. 8.5:'

.6 is an enlarged view showing' the sup-` The flexible cable which supports the ladder porting Vmeans for the ladder and illustratingthe in` transporting position is usually of stranded position of .certain supporting parts when the Y steel, or galvanized wire, or in some cases itmay ladder is in position for transportation. 1 t be made of' copperA cable to'avoid rusting or de*- 35 Referring in detail to the drawings, the ladde teriorationV by `the elements; or ordinary heavy y of `my invention as `shown comprises a Vmain manila rope may be used, but,n thisy is not so. section 10 and an extension section 12. l The main preferable on account of its shrinkage caused by t section is pivotally mounted at 14 to an A-frame wetting. e Regardlessv of `what lkind of cable or 16 fabricatedof angle iron or similar rolled struc rope isv used, it is importantuto provide means for 4 tural sections. The frame 16 is preferably sepreventing the jogging of` the ladder whenr in cured to a base 18 carried by an automobile 20 of transit. For this purpose, I provide a togglelock the type known as a light delivery truck. consisting of toggle `links 38and 40 pivotedre `The frame carries arcuate bars, one of which spectively, at 42 and 44 to the main ladder 10 .and Y is shown at 22 in Fig. ywhich is provided with the'A-frame 16.` `The links are pivotally con-v "100V a pluralityV of holes 24 which are adapted `to be `nected at 46. The link 38 carries a pin 48 which is engagedby a locking projection 26 formed on adapted to beseated ini a` notch 50 vformed inv the end of a spring pressed rod which is slidable 'link 40 when the toggle is` thrown beyond dead longitudinally within a casing 28 secured by suitcenter. The link `38 is lprovided with a Ahandle able brackets'to a I'side bar of theladder. The 39 adapted to be grasped bythe operator 111.105

locking Vprojection can befconnected or disconorder to break the toggle when it is desired to' nec'ted by exertingV aipullon a exible cord or swingthe ladder to the workingposition of Fig.

cable 30. I 1. With the toggle thrownpast deadcenter, Any suitable means vnot shown may-be pro- ,as indicated in the position of Fig. 6, it will be i vided for moving the extension Yportieri 12 relaunderstoodv that upward. motion of the right "110 tively to the main portion l0 of the ladder. This endof the .ladder is prevented because the pin 48 will be seated against the base of the notch 50 in link 40. On the other hand, the downward movement of the right end of the ladder is prevented by the cable 32. In order to compensate for any slack or eventual stretch in the cable 32, I provide a spring 52, one end of which is secured at 54, located at about midpoint of the length ofthe cable, the other end of the spring being secured at 56 to one of the members of the A-frame. This spring in addition to taking up any small amount of slack occasioned by stretch of the cable also serves as a take-up device for drawing the cable in under the frameA when the ladder is swung to its working position, as indicated in full lines in Fig.. 1 and dotted lines in Fig. 6.

Y Both the main ladder and the extension ladder section 12 are preferably provided with a double set of rungs. As illustrated in Fig. 2, the one set comprises the rungs 58 atl one side and rungs 60 atV the other side of the side rail 62. The

rungs

58 and 60 are preferably arranged in stag'- gered relationship as clearly indicated in Fig. 2. With 'such an arrangement, it will be understood ythat the workman may climb the-ladder on either set of rungs. One working at or near the top of a long ladder is apt to become soon fatigued if obligedto support his entire weight merely on the rung.

Also if he is obliged to reach upwardly or outwardly from the ladder he is usually obliged to use yone hand to steady himself so as `not to lose balance. e

To provide greater comfort for the workman and to insure, hissafety,A I provide steps vsupported'on the opposite sets of rungs,V nearthe top of the ladder and also safety means as shown in Fig. 2. The relatively wide step 64 shown at the right at the lower vside of Fig. V2 includes a plurality of slats 66 which are Ariveted or'otherwise secured to side bars, one of which is shown at'68. `This side bar gisrbent around at one extremity as indicated at r10.so as to pivotally support the step, on one of the rungs 58. There is another step of substantially the same construction as indicated at 72, this step being pivoted on one'of the rungs 60 as illustrated. The steps 64 and` 72'are connected withonev enother by supporting cables, one of which is shown'at 74:.Y EachV cable '74 engages an I-bolt 76 secured tothe outer end of the respective steps. Each I-bolt also serves to fasten a kick plate '78 to the step. Normally a spring secured tothe two bolts 82 carried by the

steps

64 and 72 tends to hold both steps folded in vagainst the correspondsupport while performing his task near the topA oi a ladder.

f In order that the workman may be free to useV both handsA without thought of steadying him'- rself against falling, I provide a safety bail. This includes av relatively stiff or rigid substantially U-shaped bar as indicated at 84. This is pivoted on suitable trunnion boltsl 86 located near the upper extremity of the ladder. The pivot point is sollocated that the safety bail can be swung into operative position at opposite sides of the ladder as indicated by full and dotted lines in Fig. 2.

This safety bail being of relatively stiff or rigid material provides means whereby the workman can be braced while leaningsidewise from the ladder. For bracing or rigidifying the bale against sidewise strain,V for example, against strain in the direction of the arrows, in Fig. 3, I provide rigidifying members secured by rivets or other suitable fastening devices 87. Each rigidifying member has prongs 88 formed at the two extremities thereof which are adapted to alternatively engage respective notches 90 formed in

brackets

92 and 94 secured to the side rails of the ladder.

When the prongs 88 interengage with the notches of the brackets, it will be understood that the bail will be adequately braced so as to enable the workman to lean sidewise against the bail in the direction of the arrow .'r. And, whensuch strain is applied on the bail, rigidifying members will prevent the bail from bending outwardly about the pivotal point86. This arrangement,r it rwill be understood, .ensures safety of the workman to freely perform his task without fear of losing balance. Y

While I have described with great particularity certain specic constructions of the embodiment vof the invention herein illustrated, itis not to ,be construed that VI am limited thereto since ino y various modifications may be made by those skilled in the art without departing from Vthe appended claims.

Vmovable with the bail and an apertured member secured to the ladder for interlocking engagement with said rigidifying member.

2. A ladder having a bail of stiff material pivotally secured near the upper extremity thereof, a rigidifying member secured to said jbail, notched brackets on opposite sides of the ladder, said rigidifying member having separate prongs adapted fory interlocking engagement with either of said notched brackets 3. A ladder having a double set of rungs, re' spective wide steps pivoted on staggered rungs, means tending to collapse said steps against certain of the rungs and a member connecting said steps whereby'part of the load of a step carried by one set of rungs can be transmitted through said member to the step carried by the other set of rungs.

y 4. The device of claim 3 wherein the steps have respective kick plates for swinging either step of the rung into supporting position, said kick plates being secured to the steps at points spacedV from fthe rungs which pivotally support said steps.

5. A portable ladder supporting apparatus comprising a frame adapted to be secured vto a vehicle, a ladder pivotally mounted on said frame,

a cable adapted to limit the movement of the ladder in one direction about its pivotal support so as to position the ladder when in transit, and a toggle joint between the ladder and said supporting frame adapted to releasably lock the ladder in a predetermined position during transit, said toggle joint including two pivotally connected members and being provided with means to limit the relative movement of said members a predetermined distance past dead center in order to hold the cable tensioned.

6. A portable vladder supporting apparatus comprising a frame Vadapted to Abe secured to a predetermined distance past deadcenter in order to hold the cable tensioned.

'7. A portable ladder supporting apparatus comprising a frame. vadapted to be secured to a a cable kconnected at one end to said frame and at the otherr endto said ladder, said cable being adapted to limit the ladder when in its inoperative position, spring means adapted to take-Yup the slack in said cable when the ladderis swung vehicle, a ladder pivotally mounted on said frame, 'i

into working position, and means for releasably locking the ladder in working position. Y

GEORGE BERKELEY REED.