US2899009A - Folding step ladder - Google Patents

Description

Aug. 11, 1959 I M. ROTH 2,899,009

FOLDING STEP LADDER Filed Aug. '25, 1958 3 Sheets-Sheet 1 INVENTOR. M l LT O N R OT H HTTURNEY W 11*," 1959 M. ROTH FOLDING STEP LADDER 5 Sheets-Sheet 2 Filed Aug. 25, 1958 INVENTOR. MILTON ROTH HT'I'DRNEY' M. ROTH FOLDING STEP LADDER Aug. 11, 1959 3 Sheets-Sheet 3 Filed Aug. 25, 1958 INVENTOR.

MILTON ROTH HTTURNEY dl States I 1 This invention relates generally to ladders, and more particularly has reference to an extensible stepladder.

Stepladders ordinally consume a large amount of space in the home, and it is, of course, desirable to avoid this as much as possible. Accordingly, one important :object of the present invention is to provide -a collapsible, extensible stepladder so designed that when .it is collapsed and stored, it will occupy a very small amount of space as compared to stepladders not having the telescopic or extensible characteristics of the present invention.

Another object is to provide a collapsible stepladder of the character stated which, when extended for use, will be characterized by its strength, resulting from the overlapping of difierent sections of the stepladder, to produce particularly effective side bracing meansonthe stepladder.

Another object .is to provide a collapsible stepladder of the character stated which will be capable of manufac- .ture as a comparatively low cost, considering the decided benefits to be obtained from the use thereof.

A furtherobject is to provide an improved latch means operable automatically responsive to extension of the stepladder, to releasably hold thesections of the .ladder in their extended positions.

A further object is to provide said latch means on both the front and rear portions of the ladder, so that each of said portions will have a self-contained latch assembly operable when said portions move into an extended position.

A further object is to facilitate the retraction of the latches when the stepladder is to be collapsed, by reason of a novel arrangement wherein swinging of the front and rear portions of the ladder into contacting relation will cause the latch means of said front and rear portions to be connected for conjoint retraction. In this way, responsive merely to swinging of ladder portions toward each other, one is enabled to operate the latches of both portions for the purpose of efiecting telescoping of .said portions to a fully retracted or collapsed condition.

A further object is to provide a collapsible stepladder as described which in at least one form of the invention will be designed to facilitate operation of the front and rear portions, so that each of them can be usable as an extension ladder. In this way, it is proposed to permit the collapsible stepladder to be readily separated into its basic component parts, to permit simultaneous use thereafter of two extension ladders.

For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawings, and to the appended claims in which the various novel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

Fig. l is a front elevational View of the stepladder according to the present invention, in a fully collapsed condition.

atent 2,899,009 Patented Aug. 11, 1959 ice Fig. 2 is a side elevational view of the ladder, fully collapsed.

Fig. 3 is a top plan view of the collapsed ladder as seen fromline 33 of Fig. 2.

Fig. 4 isa side, elevational view of the ladder in its extended or use position.

Fig. 5 is a rear elevational view of the extended ladder, as seen from theright of Fig.4.

Fig. 6 is a vertical sectional view through the ladder in its extended position, taken substantially online 6-6 of Fig. 5.

Fig. 7 is a'greatly 'enlarged, transverse sectional view through the rear portion of the ladder, taken on line 7--7 of Fig. 6-and showing the latch means of said rear .portion.

Fig. 8 is a sectional view similar to and on the same scale as Fig. 7, takensubstantially on line 88 of Fig. 6, showingoneof thelath means of the front portion.

Fig. 9 is a perspective view, on approximately the same scale as Figs. 7 and 8, of one of the latch blocks shown in Fig. 8.

Fig. '10 is a fragmentary, exploded, perspective view of the upper portion of a'rnodified form of the invention.

Referring to thedrawings indetail, the stepladder comprising the present invention includes a collapsible front .portion 1'0 and a-c-ollapsible rear portion generally designated 12 and 'hingedly connected at its upper end to the upper end of the front portion. The front portion com- -prises three'telescopicsections in the illustrated example. However, the number of sections could be increased or decreased as desired. Sa'idsections comprise, in the illustrated embodiment, an upper section 14, an intermediate section 16, and a bottom section 18.

Each of the sections 14, 16 and 18 will be described in turn. Thus, considering the construction of the upper section 14, this includes a horizontally disposed, trans versely extending upper tread or step 20, comprising the topmost step of the ladder. Step '20, as may be noted from Fig. 6, can be formed of a length of channel metal material, opening downwardly. Obviously, the surface of this and of the remaining steps could be roughened, corrugated, or otherwise formed not only to increase the strengthof the step, but also to provide a non-slip surface thereon.

In any event, step 20 at its opposite extremities is welded or otherwise fixedly secured to a pair of downwardly ex tending side rails of the top section 14, designated at 22 and having their lengths inclined slightly out of perpendicularity to the plane of the step 20 (see Fig. 6).

The respective side rails 22 are formed as outwardly facing channels each having inturned guide flanges 24 extending along its respective longitudinal edges (see Fig. 4). To reinforce the side rails along their midwidth areas, there are provided longitudinally extending reinforcing ribs 26 formed out of the material of the side rails. These cooperate with the flanges 24 in rigidifying the respective side rails;

Intermediate its ends but closer to its lower than to its upper end, each side rail has a rectangular, latch-receiving opening 28 (Fig. 4) disposed medially between the opposite sides of the side rail.

Considering now the construction of the intermediate section, this, like the top section, can be appropriately described as being generally of an inverted U-sha'pe. Thus, the intermediate section 16 includes a horizontally, transversely extending intermediate step or tread 30, also formed as a downwardly opening channel, the back flange 31 of the channel (Fig.- 6) being bent inwardly to provide clearance for pins of the latch means of the front portion, in a manner to be described in full detail hereafter.

The intermediate section includes intermediate side rails 32, the lengths of which are inclined correspondingly to the upper side rails 22. Side rails 32 telescopically receive the lower portions of the side rails 22, and to this end, have inwardly turned or rolled longitudinal guide flanges 34 embracing the flanges 24. A longitudinal reinforcing rib 35 of each intermediate side rail 32 is slidably engaged with the corresponding 26 of the adjacent, upper side rail 22. Intermediate the ends of the respective side rails 32, but closer to the lower than to the upper ends thereof, there are square, latch-receiving openings 36.

The bottom section 18 is also of the general shape of an inverted U, and has a bottom tread 38 similar to the tread 30 (Fig. 6). This is welded or otherwise fixedly secured at its opposite ends to depending lower side rails 40. These have their lengths inclined correspondingly to the lengths of the intermediate and upper side rails. Lower side rails 40 have longitudinal, inwardly turned guide flanges 42 embracing flanges-34 (see Figs. 4 and 8). To transversely brace the lower section, there is provided a crossbar 44 which can be formed of tubular metal stock as shown in Fig. 6, welded at its ends to the intermediate portions of the respective rails 40.

As will be seen from the above, the front portion 14 of the stepladder comprises a plurality of telescopi cally related sections each of which is of approximately inverted U-shape, the side rails or legs of each section telescoping in the side rails of the next lower section. When the sections are fully collapsed, the horizontally disposed treads or bight portions thereof are all in closely spaced, superposed relation as shown in Fig. 1.

When extended as in Fig. 4, the front portion has its side rails overlapped for substantial portions of their lengths as will be readily noted from Fig. 4. This provides effective bracing along the opposite sides of the front portion 10, which bracing imparts greater strength to the front portion than would normally be possessed thereby if it merely had, from its upper to its lower ends, one-piece, rigid side rails.

Turning now to the construction of the rear portion 12, the basic structural arrangement of the component sections thereof is similar to that of the front portion. Thus, the rear portion 12 includes upper, intermediate, and bottom sections generally designated 48, 50, and 52, respectively. Each of these, further, is of approximately inverted U-shape.

Considering the construction of the top section 48 of rear portion 12, this includes a transversely extending, upwardly arched handle 54 formed of tubular metal stock and projecting above the top step 20. Handle 54 at its opposite ends is welded or otherwise fixedly secured to the upper ends of top side rails 56 of rear portion 12, having (Fig. 4) inwardly turned upper guide flanges 58 extending along opposite sides of a reinforcing rib 59.

Intermediate section 50 includes a horizontally disposed crossbar 60 formed from a length of channel material faced in a downward direction. This is rigid at its oppos1te ends with depending intermediate side rails 62, havmg lnwardly turned longitudinal flanges 64, embracing slidably the flanges 58. Lower section 52 includes a crossbar 66 similar to crossbar 60 though slightly wider than crossbar 60. This is rigid at itsopposite ends with side rails 68 having inwardly turned guide flanges 70 embracing flanges 64 as best shown in Figs. 4 and 7.

Bracing the lowermost section (Fig. 5) is a crossbar 72 of tubular metal stock, welded at itsopposite endsto the intermediate portions of the lower side rails 68.

It will be seen that both the front and rear portions 10, 12 collapse similarly, being operable between fully collapsed positions shown in Fig. 2 and fully extended positrons shown in Fig. 4.

. The portions 10, 12 are hingedly connected at their upper ends, through the provision of confronting, rightangular hinge brackets 74 fixedly secured to and extend: mg rearwardly from the opposite ends of the top tread 20. The rearwardly projecting portions of the brackets 74 are in embracing relation to the uppermost section 48 of the rear portion 12, and are pivotally connected to said rear portion by hinge pins or rivets 76. The rear portion thus swings between its Fig. 2, non-use position in which it is in longitudinally contacting relation to the front portion 10, and its operative position in which it is in downwardly divergent relation to the front portion 10 as shown in Fig. 4.

Formed in' the several side rails 56, 62 and 68 are rectangular latch-receiving openings 78, 80, 82, respectively.

Referring now to Figs. 7, 8 and 9, the invention includes identical latch assemblies 84 mounted upon the undersides of the steps 30, 38, and identical latch assemblies 86 mounted upon the undersides of the crossbars 60, 66.

Considering first the construction of the latch assemblies 84 of the front portion 10, since these are identical, the description of one will sufiice for both.

Each latch assembly 84 includes an elongated latch housing 88 of rectangular cross section, extending horizontally between the opposite sides of the ladder section on which it is mounted. Thus, the upper latch assembly 84 has its housing 88 welded at its opposite ends to the inner surfaces of the side rails 32. The lower latch assembly 84 has its housing 88 welded to the inner surfaces of the lower side rails 40 as shown in Fig. 8.

In any event, each housing 88, at its opposite ends, communicates with the latch-receiving openings of the particular section on which said housing is mounted, so that the assembly shown in Fig. 8 communicates with openings 46 formed in side rails 40. Openings 46, in the preferred illustrated embodiment, are slightly smaller in area than the cross-sectional area of the housing 88.

Slidably mounted in the opposite ends of the housing 88 are elongated, solidly formed plungers or latch blocks 90, of a cross section corresponding to the internal cross section of the housing 88. Blocks 90 at their outer ends have beveled projections 92 comprising latch elements engageable in registered latch-receiving openings of the extended sections. Thus, in Fig. 8 latch elements 92 are engaged in registered openings 46, 36 of the intermediate and lower sections 16, 18, respectively.

Formed in the rear surfaces, of the latch blocks 90 are threaded recesses 93, in which are engaged the threaded inner ends of elongated, straight, sharply pointed prongs or pins 94 projecting rearwardly toward the rear portion 12 of the ladder.

A compression coil spring 96 is interposed between the latch blocks 90, exerting a continuous yielding pressure on the same tending to bias the same outwardly from one another, to engage the latch elements in the registered latch-receiving openings. In the rear wall of the housing 88 there are longitudinal slots 98 through which the pins project, the pins sliding in the slots during the. movement of the latch blocks 90 toward and away from each other.

The latch assemblies 86 are almost identical to the assemblies 84, the only difference being in the provision of flared sockets instead of pins 94. Thus, latch assemblies have male elements engageable in female elements of the latch assemblies 86.

Each latch assembly 86 thus includes an elongated housing 100 extending between and welded to the side rails of the associated section carrying the assembly. Sliding in each housing 100 are plungers or latch blocks 102 having at their outer ends beveled noses or projections 104, said blocks being biased from one another by 'a compression, coil spring 106 interposed therebetween. Each crossbar 60 and 66 has its front wall 87 partially cut away to permit the forwardly projecting flared sockets or female elements 108 to extend in positions adapted to receive the pigs 94. The front walls of the housing 100 have guide slots in which the sockets 108 are slidable.

Referring now to-Figs. 1-4, 'it'i s of cours'edesirable to provide brace means at opposite sides of ladder, connecting theextehded'front"andjrear portions-to limit the same against swinging outwardly from one another beyond their use positions shownfin 'Fig. 4, Said brace means fu'rth'er limits" the portions agaiiists'winging toward each otherfrom theiruse positions." 1

The brace means comprises elongated brace bars 103 at opposite sides of the ladder, pivoted at one end on pins 105' carried by the upper endportions of the side rails 40 of lower section 18, parts being shown broken away. At this end, brace bars 103' have longitudinal sl'ots 107 receiving the pins, said s1ots*(see Fig. 2) having lateral locking extensions 1 09- atone end, parts being shown broken away.

Thus, the brace bars 103" are s'lidably, pivotally connected to the lower section 1 8 at opposite sides thereof. When' the ladder is stored; the bracebars extend longitudinally of the lower section 18 as shown in Fig. 2' so as to occupy practically no extraspace,

When in use, the ladder appears as in Fig. 4 and the brace bars 103 are swung'to their Fig. 4.positions, having hooks 111 engageable over headed" pins 113 that projectlaterally outwardly from-the-opposite sides of the lower section 52 of rear-portion 1'2.

Obviously, other brace means may be employed, though that shown is believed to have particular advantages in respect to occupying no space when the ladder is stored while still discharging its intended function when the ladder is in use.

Referring now to Fig. 10, there is here shown a modified arrangement with respect to the hinge connection to the front and rear portions. In this form of the invention, the ladder has a front portion 10 and a rear portion 12 with front portion 10 having an upper section 14. Rear portion 12 has an upper section 56 A top step is rigid with side rails 22", while a handle 54 is rigid with side rails 56*. Thus, the ladder shown in Fig. 10 is identical in all respects to that shown in Figs. 1-9 with the exception of the hinge connection. In this form of the invention there is a transversely elongated clevis member 110, in the form of an elongated bar having rearwardly projecting extensions 112. A crossbar 114 of section 48 has forwardly projecting extensions 116 embraced by extensions 112. The overlapped extensions of the clevis members 110, 114 have openings adapted to receive an elongated hinge pin 118 extending the full width of the ladder. This has a head at one end, the other end being threaded to receive a nut 120.

The clevis members are rigid with their respective sections. It will be apparent that by removal of the nut I120, pin 118 can be taken out, separating the front and rear portions 10, 12. Each thus becomes usable as an extension ladder, independently of the other.

In both forms of the invention, and considering the normal use of the device as a stepladder, one normally stores the ladder in the Fig. 2 position. At this time, the ladder takes up very little space. At this time, further, pins 94 are engaged in sockets 108. It is also important to note that the latch-receiving openings of the several sections of the front portion are out of full registration with each other. The same is true of the corresponding opening of the sections of the rear portion 12 or 12 Therefore, the several latching plungers are held in their retracted position, when the device is collapsed as in Fig. 2.

When the device is to be used, one merely lifts the same by means of a handle 54, using the handle not only for lifting and carrying the device, but also, for facilitating swinging of the front and rear portions away from each other from their Fig. 2, longitudinally contacting positions. In any event, when the ladder is lifted, the lowermost sections automatically drop downwardly, as do the intermediate sections, so that all the sections move to their operative Fig. 6 positions. When they' move tothese positions, with rear portion 12 swung rearwardly to disengage pins 94 from sockets 108 (Fig. 6-), the openings of overlapped sections move into registration. Therefore, the latch plungers move outwardly to their Figs. 7 and 8 positions, locking the several sections intheir extended positionsautomat-ically.

Brace bars 103 are now-swungto their bracing positions, and the ladder is ready for use.

If the ladder is to be collapsed, one'merely disengages the brace bars 103. 'Then, the front and rear portions are swung toward each other. When they move into longitudinally contacting relation, pins 94 enter the sockets 1 08, so that corresponding latch assemblies 84, 86 are linked for conjoint movement. Therefore, one merely grips the sockets 108 of a latch-assembly 86, and moves them toward each other to retract the plungers 102 to which said sockets or fem-ale projections are secured. This causes the latch blocks 90 of the adjacent latch assembly 84 to also be moved inwardly, due to the engagement of pins -94 in said sockets or tubular projections 108. As soon as the four latch blocks of the interengaged sections are moved'inward'ly out of the latch-receiving openings of the extended, associated ladder sections, said associated'sections telescope. After 'thisis done=with the lower set of-latchassemblies, the operation is carried out with respect to the assemblies 84, 86-underlying step 30 and crossbar 60, respectively. This telescopes the upper section into the intermediate section. The ladder is now fully collapsed, as in Fig. 2, ready for storage.

While I have illustrated and described the preferred embodiments of my invention, it is to be understood that I do not limit myself to the precise constructions herein disclosed and that various changes and modifications may be made Within the scope of the invention as defined in the appended claims.

Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent 1s:

1. A stepladder comprising upstanding front and rear ladder portions hingedly connected at their upper ends to swing relative to each other between inoperative positions in substantial longitudinal contact with each other and use positions in which they diverge in a downward direction, each portion comprising a plurality of sections telescopically related for retraction and extension between inoperative and operative positions respectively, and means for releasably latching the several sections in said operative positions, each of the several sections of said front and rear portions being approximately of inverted U-shape, each section of the front portion including a horizontal, transversely extending tread and side rails rigid with and depending from the ends of the tread to cooperate with the tread in defining said inverted U-shape, each section of the rear portion including a horizontal, transverse cross member and side rails rigid with and depending from opposite ends of said cross member to cooperate therewith in defining the inverted U-shape of each section of the rear portion, the side rails of several sections having inwardly turned guide flanges, the guide flanges of the side rails of each section embracing the flanges of the side rails of the section next above the same, the several side rails having openings registering in the extended positions of the section to receive the latching means, said openings being out of register in the retracted positions of the several sections, said latching means comprising a plurality of latch assemblies on each of the front and rear portions, each assembly including a pair of latching plungers and spring means interposed between the latching plungers and biasing the same outwardly from each other, into the registered openings, each plunger having lateral projections, the projections of the plungers of the latch assemblies of the front portion being interengageable with the corresponding projections of the latch assemblies of the rear portion, in the inopera- 7 tive, longitudinally contacting positions of the front and rear portions.

j 2. A stepladder comprising upstanding front and rear ladder portions hingedly connected at their upper ends to swing relative to each other between inoperative positions in substantial longitudinal Contact with each other and use positions in which they diverge in a downward direction, each portion comprising a plurality of sections telescopically related for retraction and extension between inoperative and operative positions respectively, and means for releasably latching the several sections in said operative positions, each of the severalsections of said front and rear portions being approximately'of' inverted U-shape, each section of the front portion including a horizontal, transversely extending tread and side rails rigid with and depending from the ends of the tread to cooperate with the tread in defining said inverted U-shape, each section of the rear portion including a horizontal, transverse cross member and side rails rigid with and depending from opposite ends of said cross member to cooperate therewith in defining the invertedv U-shape of each section of the rear portion, the side rails of several sections having inwardly turned guide flanges, the guide flanges of the side rails of each section embracing the flanges of the side rails of the section next above the same, the several side rails having openings registering in the extended positions of the section to receive the latching means, said openings being out of register in the retracted positions of the several sections, said latching means comprising a plur ality of latch assemblies on each of the front and rear portions,;each, assembly including a pair oflatching plunger sfand springmeans interposed between the latchingplungers and biasing the same outwardly 'from each other, into the registered openings, each plunger having lateral projections, the projections of the plungers of the latch assemblies of the front portion being interengageable with the corresponding projections of the latch assemblies of the rear portion, in the inoperative, longitudinally contacting positions of the front and rear portions, the projections of one portion being of the male type and the projections of the other portion being of the female type to receive said male projections, forconjoint operation of corresponding latch assemblies of the front and rearportions when said front and rear portions are inv longitudinally contacting positions.

References Cited the file of this patent UNITED STATES PATENTS 1,712,942 Smith May 14, 1929 2,194,856 Kostuk Mar. 26, 1940 2,588,959 Campbell Mar. 11, 1952 2,827,216 Napolitano Mar. 18, 1958

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