US3386531A

US3386531A - Retractable ladder

Info

Publication number: US3386531A
Application number: US494481A
Authority: US
Inventors: Werner J Sallein
Original assignee: Werner J. Sallein
Current assignee: WERNER J SALLEIN
Priority date: 1965-10-11
Filing date: 1965-10-11
Publication date: 1968-06-04
Anticipated expiration: 1985-06-04

Description

J ne 4, 1968 w. J. SALLEIN RETRACTABLE LADDER 4 Sheets-Sheet l Filed Oct. ll, 1965 INVENTORT X Werner J. Sallein BY WW Attorneys June 4, 1968 w. J. SALLEIN 3,386,531

RETRACTABLE LADDER 4 Sheets-Sheet 2 Filed Oct. 11, 1965 4 INVENTORY Werner J. Sallein Attorneys June 4, 1968 w. J, SALLEW 3,386,531

RETRACTABLE LADDER Filed Oct. l1, 1965 4 Sheets-Sheet 5 ngvENToR. Werner" J. 50!! in Attorneys June 4, 1968 w, sALLElN 3,386,531

RETRACTABLE LADDER 4 Sheets-Sheet 4 Filed Oct. 11, 1965 lid 0/ A uz 'mv-EN'roR.

Werner J. Sallei BY M M @i Attorneys United States Patent Office Patented June 4, 1968 3,386,531 RETRACTABLE LADDER Werner J. Sallein, 2401 Ingalls St., San Francisco, Calif. 94124 Filed Oct. 11, 1965, Ser. No. 494,481

1 Claim. (Cl. 182-207) This invention relates generally to retractable ladders and more particularly to inclined fire escape ladders.

An object of the present invention is to provide a new and improved retractable ladder.

Another object of the present invention is to provide a ladder which can be quickly released and lowered swiftly but under controlled conditions to prevent ladder destruction.

A further object of the present invention is to provide a ladder of the type described which is economical to construct and install.

Still another object of the present invention is to provide a retractable ladder which is lightweight, compact, yet durable and strong enough to hold several persons at one time.

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 claim.

Referring to said drawings (four sheets):

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

FIGURE 2 is a side elevational view of the ladder in its expanded position.

FIGURE 3 is a front elevation view of the ladder taken substantially along the line 3-3 of FIGURE 2.

FIGURE 4 is a side elevation view of the ladder in its retracted position.

FIGURE 5 is an enlarged front elevation view of a portion of the ladder taken substantially along the line 5-5 of FIGURE 2 with portions broken away for purposes of illustration.

FIGURE 6 is an enlarged side elevation view of a portion of the ladder in the partially retracted position with portions broken away for purposes of illustration.

FIGURE 7 is a cross-section view of the device taken substantially along the line 77 of FIGURE 6.

FIGURE 8 is a side elevation view of a modified form of the ladder shown in the expanded position with portions broken away for purposes of illustration.

FIGURE 9 is an enlarged section of a portion of the device taken substantially along the line 9-9 of FIG- URE 8.

FIGURE 10 is an enlarged view of a portion of the device taken substantially along the line 10-40 of FIG- URE 6.

The ladder of the present invention is for an elevated structure such as a fire escape balcony 6 to provide temporary passage to a lower elevation and consists briefly of a first section 7 adapted for mounting on the elevated structure and having a pair of downwardly extending, spaced, substantially

parallel stringer members

8 and 9 joined by a plurality of substantially horizontally spaced tread members 11, the stringer members each being formed with an

elongated flange member

12 and 13 disposed in opposed directions; a second section member 16 mounted for sliding engagement on and longitudinally of the first section, and having a pair of

stringer members

17 and 18 each being formed with a

flange member

21 and 22 disposed in opposed directions and forming with the flanges of the first section an inwardly and outwardly turned transversely interlocking, longitudinally slidable fit; stop means limiting the longitudinal extension of the sections to provide an overlapping of the sections; the treads being transversely spaced on the stringers from the flanges so as to permit sliding receipt of the flange of the other section therebetween and to provide interlocking at the overlapped section between the treads ofone section and the flange of the other section to provide horizontal stability; and means for retracting the second section.

In a three section ladder the second section is mounted for sliding engagement on and longitudinally of the first section and has a pair of channel shaped stringer members consisting of

webs

26 and 27 and

first flanges

21 and 22 and

second flanges

29 and 30 disposed in opposed directions and the first flanges forming with the flanges of the first section an inwardly and outwardly turned transversely interlocking, longitudinally slidable lit. The third section member has a pair of spaced substantially parallel stringer

members

36 and 37 joined by a plurality of spaced tread members, each of the stringer members being formed with

elongated flange members

39 and 40 disposed in opposed directions, these flanges and the second flanges of the channel forming an inwardly and outwardly turned transversely interlocking, longitudinally slidable fit preventing transverse movement of the second and third sections.

While two and three section ladders may be built as above described, most installations will require a plurality of sections because of the distance of the fire escape balcony above the sidewalk or street or the necessity of retracting the ladder into a compact unit. The preferred form of the invention therefore consists of a plurality of first sections substantially similar to section 7 above described but having a pair of elongated spaced, substantially parallel channel members formed with

webs

46 and 47 and inwardly disposed

flanges

12, 13, 48 and 49. The second sections, likewise, are formed with channel members as above described. The first and second sections are arranged in alternating order and are disposed so that a flange of one section is interlocked with the flange of a succeeding section to prevent transverse relative movement between sections. Referring to FIGURE 7, the interlocking relationship between the channel-shaped stringers and the treads may be seen. A unique feature of the present invention is the fact that all of the channels are precisely the same size, shape and weight. As may be seen,

flanges

48 and 49 of the first section are turned inwardly while

flanges

29 and 30 of the second section are turned outwardly. Surface 51 of flange 48 is in mating sliding engagement with surface 52 of flange 28 and in like manner surface 53 of flange 49 is in mating sliding engagement with surface 54 of flange 30.

Transverse motion is prevented since the end of flange 29 is in sliding engagement with web 46 and the end of flange 30 is in sliding engagement with web 47.

The second section is in similar mating engagement with the third section wherein surface 56 of flange 21 is in mating sliding engagement with surface 57 of flange 39 and surface 58 of flange 22 is in mating sliding engagement with surface 59 of flange 40.

The interlocking between the second and third sections prevents transverse motion since flange 21 is in sliding engagement with web 61 and flange 22 is in sliding engagement with web 62.

In the aforesaid construction, the channel stringers co-act with the horizontal treads in preventing relative horizontal displacement of the adjoining sections. To accomplish this, tread 71 connected to

webs

46 and 47 is spaced from the face 54 of flange 49 a sufficient distance to permit receipt of flange 30 with a minimum clearance between the edge 72 of the tread and outer face 73 of flange 30. Likewise, edge 72 is spaced from flange face 51 a suflicient distance to permit receipt of flange 29 leaving a minimum clearance between edge 72 and face 74 of flange 29. In like manner, tread 76 is connected to webs 61 and 62 so that edge 77 clears faces 78 of flange 21 and face 79 of flange 22. Referring to FIGURES 6 and 7, section 16 is prevented from moving in a counter-clockwise direction by flanges 21 and Z2 binding against

flanges

12 and 13 and

flanges

21 and 22 binding against tread 71. Clockwise rotation of section 16 is prevented by

llanges

21 and 22 binding against flanges 12 and i3 and

flanges

21 and 22 binding against tread 31.

The stop means limiting the longitudinal extension of the sections here consists of stops 36 and 87, connected to

channels

36 and 37 respectively which abut with stops 91 and 92 mounted on the webs 95 and 94 of

channels

96 and 97 respectively. The stops are located so that the top two treads of the lower section are in horizontal alignment with the bottom two treads of the next to the bottom section.

Stringers

36 and 37 are prevented from moving out of engagement with

stringers

17 and 18 by stop members 101 and 162 mounted on

webs

26 and 27 respectively and which abut with stops 104 and 105 mounted on flanges 39 and 4%) respectively. The aforesaid stops are located so that there is an overlapping of at least two treads on each section.

Second section 16 is prevented from moving out of engagement with first section 7 by means of stop members 108 and 169 mounted on

flanges

48 and 49 respectively and stops 111 and 112 mounted on

webs

26 and 27 respectively.

The retractable ladder of the present invention may be easily retracted to an elevated position by a drum and pulley arrangement which consists briefly of a pipe 114 mounted for rotation on angles 115 and 116 connected to opposite facing

angles

117 and 118 connected to the upper ends of

stringer members

8 and 9. Retaining

rings

121 and 122 prevent transverse movement of the pipe. A portion 126 of the pipe serves as a drum about which the cable 127 is wound. Drum ends 128 and 129 keep the cable within section 126. A crank arm 131 having a manually engageable handle 132 is connected to the pipe for reeling the cable and retracting the ladder. Cable 127 extends downwardly from the drum through a cable sheave 136 connected to the lower end of channel 96, thence across the ladder to sheave 137 connected to the lower end of channel 97 and thence upwardly to a fixed connection 138 on the lower side of the balcony 6.

The ladder is retained in the retracted position by a ratchet wheel 141 mounted for rotation on pipe 114 and connected by a pin 142 connected to a lever 143 pivotally mounted at point 144 and connected to angle 118. Movement of lever 143 so that the pin disengages ratchet wheel 141 permits the ladder to descend to the lower elevation.

In operating the ladder to retract it to its elevated position, handle 132 is rotated so that the

lower channels

96 and 97 are raised. When the stops 91 and 92 approach the upper end of channels 88 and 89 they abut against

stop members

146 and 147 mounted on flanges 151 and 152 of webs 61 and 62. As the crank continues to rotate stops 104 and 105 approach and abut stops 111 and 112 thus raising the second section member 16. The crank rotation is continued until the upper ends 157 and 158

strike stop members

161 and 162 mounted on the upper end of first section member '7.

Another important feature of the present invention is the fact that the ladder may be equipped with hand rails which retract with the stringer members into the compact form shown in FIGURE 4. Hand rail 164 consisting of a metal bar is connected to the outside of the web 46 by

bracket members

165 and 166. Hand rail 158 is connected to the outside of Web 46 by bracket members 169 and 179. The hand rails need only be mounted on every other section so that in the four section ladder as shown in FIGURE 1 hand rails 171 and 172 are connected respectively to

stringer members

36 and 37 by brackets 1'74, 175, 176, 177, 178 and 179. As may be seen in FIGURE 1, the aforesaid hand rails overlap at their ends to maintain continuity of the railing. It may be noted that hand rails 171 and 172 are offset so as to be in close proximity with the ends of

rails

164 and 168.

Where it is necessary to provide a ladder having wider tread widths so as to meet fire or building code requirements, it is possible to position the stops so that there is an overlapping of the adjacent sections thus providing at least two horizontally aligned treads for each step. Such a modified form is shown in FIGURE 8 and is, for the most part, identical to the preferred form of the invention previously described. It may be noted that for a given elevation the sections are longer in order to provide the overlap. The portions of the ladder shown are here designated as stringer member 8a, stringer member 18a, stringer member 37a and stringer 97a. The rails shown are identical in construction to the previously described rails and are here shown as rail 164a and rail 172a.

In the extended position, stop 168a on stringer 8a abuts stop 111a preventing further movement of stringer 17a. Stop 102a on stringer 18a abuts stop a preventing further extension of stringer 37a and stop 87a on stringer 37a abuts stop 92a on stringer 97a preventing movement thereof.

In retractin" the ladder shown in FIGURE 8, stop 92a picks up stop 147a lifting stringer 37a. Stop a picks up 112a (not shown) thus raising stringer 18a.

I claim:

1. A retractable ladder comprising, a plurality of interengaging slideably attached intermediate and adjacent ladder sections, each section comprising a pair of laterally spaced parallel longitudinally extending stringer members and uniformly longitudinally spaced transversely extending tread members secured at their opposite ends to said stringer members, said stringer members being of channel shaped cross-section to provide in each instance a web and parallel side flanges and the stringer members of successive sections being turned 180 with the flanges of the stringer members of said intermediate section positioned within the channels of the stringer members of said adjacent sections thereby providing telescopic engagement of said sections for movement between retracted and extended positions, said ladder being adapted for mounting in a vertically inclined atitude in its extended position and said sections being formed in such position to place all of the tread members of said intermediate section in horizontal juxtaposition to tread members of adjacent sections, said tread members being of inverted channel shaped cross-section to provide a flat top web and depending side flanges, the lower ends of one of said flanges of each of said treads being spaced from one of said flanges of the attached stringer member to provide a guideway slideably receiving the flange of the telescopically attached stringer member, said top webs of said juxtaposed tread members being positioned in said extended inclined position of the ladder in horizontal co-planar relation to cooperatively provide a fiat horizontal double width tread.

References Cited UNITED STATES PATENTS 2,836,336 5/1958 Hansen 182-85 2,901,056 8/1959 McConologue l8285 FOREIGN PATENTS 1,133,249 7/1962 Germany.

REINALDO P. MACHADO, Primary Examiner.

Claims

1. A RETRACABLE LADDER COMPRISING, A PLURALITY OF INTERENGAGING SLIDEABLY ATTACHED INTERMEDIATE AND ADJACENT LADDER SECTIONS, EACH SECTION COMPRISING A PAIR OF LATERALLY SPACED PARALLEL LONGITUDINALLY EXTENDING STRINGER MEMBERS AND UNIFORMLY LONGITUDINALLY SPACED TRANSVERSELY EXTENDING TREAD MEMBERS SECURED AT THEIR OPPOSITE ENDS TO SAID STRINGER MEMBERS, SAID STRINGER MEMBERS BEING OF CHANNEL SHAPED CROSS-SECTION TO PROVIDE IN EACH INSTANCE A WEB AND PARALLEL SIDE FLANGES AND THE STRINGER MEMBERS OF SUCCESSIVE SECTIONS BEING TURNED 180* WITH THE FLANGES OF THE STRINGER MEMBERS OF SAID INTERMEDIATE SECTION POSITIONED WITHIN THE CHANNELS OF THE STRINGER MEMBERS OF SAID ADJACENT SECTIONS THEREBY PROVIDING TELESCOPIC ENGAGEMENT OF SAID SECTIONS FOR MOVEMENT BETWEEN RETRACTED AND EXTENDED POSITIONS, SAID LADDER BEING ADAPTED FOR MOUNTING IN A VERTICALLY INCLINED ATITUDE IN ITS EXTENDED POSITION AND SAID SECTIONS BEING FORMED IN SUCH POSITION TO PLACE ALL OF THE TREAD MEMBERS BEING OF INVERTED SECTION IN HORIZONTAL JUXTAPOSITION TO TREAD MEMBERS OF ADJACENT SECTIONS, SAID TREAD MEMBERS BEING OF INVERTED CHANNEL SHAPED CROSS-SECTION TO PROVIDE A FLAT TOP WEB AND DEPENDING SIDE FLANGES, THE LOWER ENDS OF ONE OF SAID FLANGES OF EACH OF SAID TREADS BEING SPACED FROM ONE OF SAID FLANGES OF THE ATTACHED STRINGER MEMBER TO PROVIDE A GUIDEWAY SLIDEABLE RECEIVING THE FLANGE OF THE TELESCOPICALLY ATTACHED STRINGER MEMBER, SAID TOP WEBS OF SAID JUXTAPOSED TREAD MEMBERS BEING POSITIONED IN SAID EXTENDED INCLINED POSITION OF THE LADDER IN HORIZONTAL CO-PLANAR RELATION TO COOPERATIVELY PROVIDE A FLAT HORIZONTAL DOUBLE WIDTH TREAD.