US3263773A - Inclined collapsible ladder - Google Patents

Description

Aug. 2, 1966 w. J. SALLEIN INCLINED COLLAPSIBLE LADDER 3 Sheets-Sheet 1 Filed April 15, 1964 INVENTOR.

Werner J. 'Sallein Attorney Aug. 2, 1966 W. J. SALLEIN INGLINED COLLAPSIBLE LADDER Sheets-$heet 2 Filed April 15, 1964 INVENTOR.

Werner J. Sal/ein ,9 O1, )4; Attorney Aug. 2,

Filed April 13, 1964 1966 w. J. SALLEIN 3,263,773

INCLINED COLLAPSIBLE LADDER 3 Sheets-Sheet 5 INVENTOR. F i g. 9 Werner J. Sallem Attorney United States Patent 3,263,773 INCLINED COLLAPSIBLE LADDER Werner J. Sallein, 1350 Natoma St., San Francisco, Calif. Filed Apr. 13, 1964, Ser. No. 359,234 2 Claims. (Cl. 182158) This invention relates generally to collapsible ladders, and more particularly is directed to a collapsible ladder of the type mounted on a balcony for use as a fire escape.

One object of the present invention is to provide a collapsible ladder utilizing lazy tongs construction which is expandable at an incline to afford ready and safe descent thereon and which is easily raised to a collapsed position for compact unobstructing storage.

Another object of the present invention is to provide a ladder of the type described having planar tread members which are pivotally mounted for collapsing with the ladder and having handrails extending the full length of the ladder which are also collapsible into compact form when the ladder is in its raised position.

A further object of the present invention is to provide a ladder of the type described which is readily installed on a fire escape balcony without need for complex connections to the building walls or balcony.

Still another object of the present invention is to provide a collapsible ladder of the type described which is inexpensive to manufacture, which is durable and strong enough to hold several persons at one time, and which can be quickly and easily operated to move into either raised or lowered position.

The invention possesses other objects and features of advantage, some of which of the foregoing will be set forth in the following description of the preferred form of the invention which is illustrated in the drawings accompanying and forming part of this specification. It is to be understood however, that variations in the showing made by the said drawings and description may be adopted within the scope of the invention as set forth in the claims.

Referring to said drawings (three sheets):

FIGURE 1 is a perspective view illustrating a collapsible ladder embodying the present invention and shown in its expanded lowered position.

FIGURE 2 is a front elevation view of a ladder similar to the one shown in FIGURE 1 in its lowered position.

FIGURE 3 is a partially cross sectioned side elevation view of the ladder in FIGURE 2, taken along the line 3-3 as shown in FIGURE 2.

FIGURE 4 is a side elevation View of the ladder in FIGURES 2 and 3, but shown in its raised collapsed position.

FIGURE 5 is a cross sectional view taken along the line *55 as shown in FIGURE 3.

FIGURE 7 is a partially cross sectioned front elevation view, with portions broken away, taken along the line 6-6 as shown in FIGURE 2.

FIGURE 7 is a partially cross sectional front elevation view taken along the line 77 as shown in FIG- URE 6.

FIGURE 8 is a fragmentary view taken along the line 8-8 as shown in FIGURE 6.

FIGURE 9 is a fragmentary front elevation view taken along the line 9-9 as shown in FIGURE 4.

There is shown in the drawings an inclined collapsible ladder 11 embodying the present invention and comprising a pair of spaced parallel channel members 12 and 13 each inclined at an angle from vertical, a pair of expandable lazy tongs 14 and 16 mounted on the channel members 12 and 13 and connected together by a plurality of spaced rods 17 which form the central pivot connections 18 for each lazy tongs. The rods 17 have their end portions guided in the channel members 12 and 13 for controlling the expansion of the lazy tongs to a direction 3 ,263,773- Patented August 2, 1966 generally parallel to the angle of the channel members. A plurality of spaced generally planar tread members 19 extend transversely between the lazy tongs 14 and 16 and are movable therewith. Stop means are provided for limiting the extent to which the lazy tongs can be expanded for positioning the tread members 19 generally horizontally when the lazy tongs are fully extended. At least one handrail 21 is pivotally mounted on one of the lazy tongs for positioning generally parallel to the channel members 12 and 13, regardless of the extent to which the lazy tongs are expanded.

In more detail now, the lazy tongs 14 and 16 are of generally conventional construction, and each includes a first plurality of parallel links 22 pivotally connected with a second plurality of parallel links 23. As noted, the rods 17 form the central pivot connections 18 between corresponding pairs of links 22 and 23, While stub shafts 24, as depicted in FIGURES 6 and 7, form the pivotal connections between the ends of the links 22 and 23. In a preferred form of the invention, a support frame 26, having a pair of spaced generally triangular members 27 and 28, is pivoted for mounting securely on a balcony 29 or other similar structure disposed above a ground surface 31 or the like. The channel members 12 and 13 have bracket portions 32 as best shown in FIGURE 5, whereby the channel members are removably secured to the frame members 27 and 28 by means of bolts 33 or the like.

The uppermost rod 17, denoted by the numeral 17a, is secured transversely between the upper end portions of the channel members, thus anchoring the lazy tongs to the frame 26. A plurality of next uppermost rods 17, which as shown include three rods denoted 17b, have their end portions extending transversely through longitudinal slots 34 provided in the upper portions of the channel members. The lowermost rod 17b is engageable with the lower end wall of the slots 34 to provide the aforesaid means for limiting the extent of downward movement of the lazy tongs. The remainder of the rods 17, denoted 170, are slightly shorter than the rods 17b and are all slidable in the inner longitudinal recesses defined by the channel members 12 and 13 for constraining the angle of inclination of the ladder to that of the channel members. An arcuate flange portion 35 is provided adjacent the lower end of each channel member to guide the rods 17 into the channels when the ladder is raised.

The preferred form of connection between the links 22 and 23 and the rods 17 is depicted in FIGURE 5, wherein the rod 17 is seen to extend transversely through central holes in the links. A washer 36 is interposed between the links 22 and 23, and washers 37 and 38 are respectively positioned on the other sides of each of the links. Resilient snap rings 39 and 41 are secured in circular grooves provided on the rod 17 outwardly adjacent the washers 37 and 38 for restraining the links 22 and 23 against axial movement on the rod 17. For the rod 17b as depicted in FIGURE 5, at least one washer 42 is disposed outwardly adjacent the channel member 13, with a snap ring 43 positioned adjacent the washer 42, for guiding the rod 17b in its movement in the slot 34. Similar central pivot connections as that shown in FIGURE 5, are provided for all the links.

As regards the tread members 19, these members are seen to be of generally U-shaped cross section having a depending forward edge 44 and a depending rearward edge 46, as best shown in FIGURE 6. The forward portion of each tread member is supported on one of the rods 17, and a pair of stub shafts 47 are rigidly secured as by welding to the lower edge of the corresponding links 23 of each lazy tongs for supporting the rearward portion of each tread member. A pair of strap members 48 are secured between the bottoms of the edges 44 and 46 adjacent each end of the tread members to retain them on the rods 17 and stub shafts 47, as best shown in FIGURES 5 and 6. It will be appreciated that the tread members 19 as thus mounted will remain parallel as the lazy tongs are expanded or collapsed, and that the angular position of the tread members is dependent on the extent of expansion of the lazy tongs. In the embodiment of the ladder as illustrated, the slots 34 and lowermost rod 17b coact so that when the lazy tongs are fully expanded, as limited by the lower end wall of the slots 34, the upper surfaces of the tread members 19, are disposed in a generally horizontal position. Preferably, as depicted in FIG- URE 6, the treads are slightly inclined into the ladder to assure safe footing on the treads.

An important feature of the instant ladder relates to the aforementioned handrail 21, which is disposed parallel to the channels 12 and 13 and is collapsible with the lazy tongs as the ladder is raised. The handrail 21 is mounted on the lazy tongs 14 on two of the links22 thereof, which have extension portions 22a and 22b as shown in FIG- URES 3 and 6. Brackets 49 and 51 are respectively pivotally mounted on the link extensions 22a and 22b, with the lower end portion of the rail 21 being rigidly secured to the lower bracket 49. A tubular guide member 52 forms a portion of the upper bracket 51, with the rail 21 being slidable through the member 52 as the lazy tongs are expanded or collapsed. Thus, with the ladder collapsed as shown in FIGURE 4, the member 52 is disposed adjacent the lower end of the rail 21, while the member 52 is disposed adjacent the upper end of the rail 21 when the ladder is lowered as in FIGURE 3.

' In order to provide handrails along the full length of the ladder 11, it is preferable that additional handrails 21a and 21b are provided on the lazy tongs, and are collapsi ble therewith. In this regard, additional brackets 53 and 54 are respectively pivotally mounted on link extensions 22c and 22d, as indicated in FIGURE 3. The rail 21a is secured rigidly to the bracket 51, and is slidably disposed through a guide member 56 mounted on the bracket 53. Similarly, the rail 21b is secured to the bracket 53, and is slidable through a guide member 57 secured to the bracket 54. As shown, the rails are positioned for relative longitudinal movement in overlying relation to one another. Preferably, the three rails 21, 21a and 21b are provided only on the lazy tongs 16, while only the lower two rails 21 and 21a are provided on the other lazy itongs 14 in order that free access be afforded to the ladder from the balcony 29. A hand grip 58 may be secured to the channel member 12 adjacent the lazy tongs 14 to assist those mounting the top of the ladder.

To enable raising the ladder into its collapsed storage position, a winch 59 is secured to the frame 26, and includes a crank handle 61. A cable 62 is wound on to a reel 63 of the winch, and is connected to one of the lower tread members 19 by means of an eye 64, as shown in FIGURE 6. A release lever 66 is provided for releasing the winch to lower the ladder under its own weight, and preferably, the handle 61 is adapted to be automatically disengaged from the reel 63 by means of a conventional .throwout device 67, as shown in FIGURE 9, so that rotation of the handle 61 does not endanger persons closely situated.

In operating the instant ladder, when the winch is released by means of the lever 66 the lazy tongs commence to expand under the force of gravity. The rods 17 are guided in the channel members 12 and 13 so that the angle of descent of the ladder is constrained to a direction parallel to the channel members. When the lowermost rod 17b comes into engagement with the lower end wall of the slots 34 the lazy tongs are restricted against further expansion, and in this position the tread members 19 are substantially horizontally disposed. By utilizing the correct number of links 22 and 23 the length of the ladder will conform to the height between the balcony 29 and ground surface 31. In order to raise 4 the ladder, the winch handle 61 is operated to wind the cable 62 onto the reel 63, thus collapsing the lazy tongs upwardly. As the ladder is raised off of the ground, there is some tendency to flex toward a vertical position. Consequently, the arcuate flange 35 engage the rods 17c as they are moved upwardly and guides them into the channel members 12 and 13.

With regard to the ease and simplicity of mounting the instant ladder on the balcony 29, there is provided a U-shaped support brace .68 secured between the lower end portions of the channel members 12 and 13. This member enables the lazy tongs, channel members, and handrails to be assembled as a separate unit prior to mounting on the balcony. At the time the building is being constructed, or when desired, the relatively simple support frame 26 is secured by itself to the balcony, by Welding, bolts, or other suitable means. Then, after the support frame is in place, the unit consisting of the channel members, lazy tongs, etc., can be readily secured to the frame by means of the brackets 32 and bolts 33 as described here-inabove. Thus, there is eliminated the problem of having to secure the whole ladder and support frame at the same time to the balcony.

I claim:

1. A collapsible ladder comprising, a support, a pair of spaced parallel extendible lazy tongs mounted on said support each including a first plurality of parallel links pivotally connected with a second plurality of parallel links and a plurality of spaced rods extending transversely between said two lazy tongs to form the pivot connections between said links thereof, a plurality of generally planar tread members extending transversely between said two lazy tongs and being formed with elongated underlying slots receiving said rods adjacent the forward portions of said threads a plurality of stub shafts one secured to each link of one set of said plurality of links and extending into said slots and positioned to engage and support the rearward portions of said tread members, said tread members being mounted on said lazy tongs for generally horizontally positioning when said lazy tongs are fully expanded.

2. An inclined collapsible ladder comprising, a support frame adapted for mounting in upwardly spaced relation to a ground surface, a pair of spaced parallel generally elongated channel members secured to said frame and having longitudinally extending confronting channel recesses, said channel members being disposed in generally vertical planes and inclined at an angle from vertical, said channel members each having a longitudinally extending slot disposed adjacent the upper end thereof, said channel recesses being opened at the lower ends thereof with downwardly turned arcuate flanges being provided on said channel members adjacent said lower ends, a pair of spaced parallel expandable lazy tongs mounted on said frame each including a first plurality of parallel links pivotally connected with a second plurality of parallel links and a plurality of spaced rods extending transversely between said two lazy tongs to form the central pivot connections between said links thereof, an upper one of said rods being secured to said frame adjacent the upper ends of said channel members, a plurality of the next uppermost rods extending laterally outwardly of said lazy tongs and transversely through said slots for longitudinal movement therein, the remainder of said rods being shorter than the latter plurality of rods and having their end portions slidably guided in said channel recesses for longitudinal movement therein, the lowermost one of said rods that extend through said slots being engageable with the lower ends of said slots to limit the downwardly extending movement of said lazy tongs, a first generally elongated handrail mounted on first and second ones of said first plurality of links and being positioned generally parallel to said channel members, said first handrail being pivotally secured to said first and second links and being mounted for longitudinally slidable movement in relation to said second link, a second generally elongated handrail being mounted on said second link and a third link of said first plurality of links and being positioned in generally parallel to said first handrail but longitudinally displaced in relation thereto, said second handrail being pivotally mounted on said second and third links and being longitudinally slidable in relation to said third link, said third link being positioned upwardly relative to said second links and said second link being positioned upwardly to said first link, said first and second handrails being positioned for generally longitudinal relative movement in overlying relation to one another, a plurality of generally planar tread members extending transversely between said two lazy tongs and being formed with elongated underlying slots receiving said rods adjacent the forward portions of said treads, and a plurality of stub shafts secured respectively to corresponding ones of said second plurality of links and extending into said slots adjacent the rearward portions thereof, said tread members being mounted on said lazy tongs for generally horizontal positioning when said lazy tongs are fully expanded.

References Cited by the Examiner UNITED STATES PATENTS REINALDO P. MACHADO, Primary Examiner.

HARRISON R. MOSELEY, Examiner.

Claims (1)

1. A COLLAPSIBLE LADDER COMPRISING, A SUPPORT, A PAIR OF SPACED PARALLEL EXTENDIBLE LAZY TONGS MOUNTED ON SAID SUPPORT EACH INCLUDING A FIRST PLURALITY OF PARALLEL LINKS PIVOTALLY CONNECTED WITH A SECOND PLURALITY OF PARALLEL LINKS AND A PLURALITY OF SPACED RODS EXTENDING TRANSVERSELY BETWEEN SAID TWO LAZY TONGS TO FORM THE PIVOT CONNECTIONS BETWEEN SAID LINKS THEREOF, A PLURALITY OF GENERALLY PLANAR TREAD MEMBERS EXTENDING TRANSVERSELY BETWEEN SAID TWO LAZY TONGS AND BEING FORMED WITH ELONGATED UNDERLYING SLOTS RECEIVING SAID RODS ADJACENT THE FORWARD PORTIONS OF SAID THREADS A PLURALITY OF STUB SHAFTS ONE SECURED TO EACH LINK OF ONE SET OF SAID PLURALITY OF LINKS AND EXTENDING INTO SAID SLOTS AND POSITIONED TO ENGAGE AND SUPPORT THE REARWARD PORTIONS OF SAID TREAD MEMBERS, SAID TREAD MEMBERS BEING MOUNTED ON SAID LAZY TONGS FOR GENERALLY HORIZONTALLY POSITIONING WHEN SAID LAZY TONGS ARE FULLY EXPANDED.

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