US2393759A

US2393759A - Disappearing stairway

Info

Publication number: US2393759A
Application number: US502292A
Authority: US
Inventors: Willard D Eakin
Original assignee: Individual
Current assignee: Individual
Priority date: 1943-09-14
Filing date: 1943-09-14
Publication date: 1946-01-29
Anticipated expiration: 1963-01-29

Description

Patentedl Jan. 29,1946

UNITED 4's'rli'iisis PATENT o Fries Dlssrrnaamc s'rslawn Willard n; pekin, Akron, ome Appiiestien september 14', 194s, serial No. stam c-cisims. ici.. zza-soi 'rms invention relates to disappearing steir- Wy.

Its chief objects are:

To provide simplicity, economy anddurability;

To provide a stairway and associated mechanism adapted to be stored wholly within the and from use position fromeither the upper floor or the lower floor;

To provide a trap-door balancing each other that they can be moved to and from use position with little eifort, and to provide an "over-center eilect so that the assembly will be rmly held in use position by lllvlty and will be rmly held in Stored P051- tion by gravity:

To avoid the use of vcable-and-pulley devices and of springs for counteracting the weight of the stair. and thus to eliminate'their tages of wear'. breakage and danger;

To provide numerousand widely spaced points of support for the stair when in use and when vbeing moved to and froml stored position;

To provide automatically presented and automatically stored hand rails;

To provide other advantages which arev in'- I heren't in the structure herein described.

Of the accompanying drawings:

and stair so counter- I The track-ways I1 are the same in cross-sectional form as track-ways, such as that shown at I8, which are secured by screws I9, I9 (Fig. 3)

to the outer faces' of the side members of the 'l stair, and the rollers I6 are of the same construction as the rollers that are adapted to run in the track-ways I8, one. or which rollers is shown at' ,20 (see Fig. 3).

Secured to each of the joists, I2, by screws 2|,

2|, is a face plate 22 formed with two holes in which respectively are riveted a large, shouldered axle-stud 23 and a smallenvshouldered axle-stud 24, projecting toward the middle of the stair well.

Each of the studs 24 is connected with a stud 25 projecting 'from the adjacent side of the stair by a thin, flat link member 28, which is adapted to act as one arm of a toggle, of which the other arm is the upper portion of the stair, for shifting the upper end of the stair to the right, along disadvanthe guide-ways I'I, when the stair is swung upward about the moving axis I8. Thus the upper end of the stair moves to the position a as its lower end moves to the position b.

This shifting-axis feature permits the useof a stair almost as long as the ceiling joists, so that -it is not excessively steep when in use, and4 at the same time provides upper and lower landings of adequate size.

An opening 2'I in the oor of the upper room is adapted to .be closed by a trap-doorn which is hinged at 28. The trap-door preferably but not necessarily consists ofiiloorins boards I3, I, held together preferably by a sheet-metalv plate n secured te their under faces by screws such as the screw 3| (Fig. 4) along the side marginsof themetal plate; near the ends of the Fis. 1 is a vertical middle section of a stair and associated structure embodying my invention in its preferred form. i

Fig. 2 is a section, on a larger scale,on the indirect line 2--2 ofFig. 1.

Fig. 3 is a section on linel--i of Fig.` 1.

-4 is a section on line l--I of Fig. i. Referring to the drawings, the mechanism; is shown installed lin a `room of which thezstuddins .is shown at I0, i.: the plates at II,'.II. one of the joists at I2, boards of the upper floor at I3, Il, and the floor ofthe lower room at I4.

The stair, I. is provided on'each side of its upper end with an outwardly projecting axleboards I3, sothat the metal plate serves as a bridge member to.v give the door great strength for supporting weight whether or not the plate litself directly engages the joists.l Permissibly it can come to'rest upon the .upper edges o f'the axle-stud plates 22 (compare Figs. 4 and il).

Secured to the lower face of the plate Il are a pair of guide-ways of which one is shown at I2 for guidingvresp'ective rollers such .as theroller 33; which can be of the same size'andA construction as/ the two other pairs of rollers II' and 20.-

and-roller, assembly Il,l the rollers being of horiliontallyv in respective track-ways, such as the one shown atI'I. secured to the respective joists' at the two sides o! the -grooved or waisted form and adapted to run.

For economy each or lthe six rollers vcan be formed or three sheet-metal discs spot-welded together. providingsuch mechanical' connection be tween the stair lIl and the trap-door 2l4 that they will counter-balance each other, with the "overy center enect above referred to inthe statement 'oi objects, the rollers are mounted respectively ,uptm the` upper ends. and the rollers."

mounted respectively upon the lower ends, of a pair of actuating levers of which one is shown at 34, said levers being fulcrumed respectively upon the axle-studs 23.

When the trap-door 28 and its metal reinforcing plate 30 are oi sufiicient size and weight they can alone serve as a suiiicient counter-weight for the stair, but if the proportions and weights of parts are not such as to provide adequate counter-weight without more a special counter-weight 35, adapted to be received between steps of the stair, can be secured to'the under face of the door.

lThe structure thus far described provides a simple, dependable, safe and durable mechanism for installations where hand-rails paralleling the stair are not required, the nearly vertical actuating levers 3d and the angularly disposedlinks- 2E serving well as hand-holds,

Such construction is well adapted, however, for combinationvwith a pair of 'hand-rails, such as the one shown at 36, hinged respectively upon the axle-studs 2d and at a lower position connected with the stair by parallel-motion links such as the link 3l having the same effective length, between pivots, as the toggle-links 2t.

Bracket-like clips such as those shown at @t andv 39 can bemounted on the link @l and handrail 36 respectively and adapted to receive the actuating lever 3H as the stair comes to use position, for giving the hand-rail additional points of support against lateral displacement.

The mechanism can be operated either from the upper iloor, by manual engagement ofthe f trap-door, which preferably is provided with an in-set handle ring 40, or from the lower floor, by manualengagement of a pull cord die attached to the stair. Only a small force is required for moving the assembly from the dotted-line stored position to the full-line use position, or back to the .stored position. The stored position of the actuating lever 34 is shown at c and that of the hand-rail 38 at d.

A panel 4l of ceiling material or of ply-wood can be secured to the under side of the stair. so that when the stair is in stored position the opening in the ceiling will be closed by it. It also serves the purpose of risers, which is of some importance in View of the fact that some persons dislike to use stairs thatv they can see through.

Preferably a bar l2 of triangular cross-section is secured to the lower end of the stair and, like the panel, projects to the middle plane of the joist at each side, to serve as a; large-area foot for the stair and as a stop for the stair in its stored position, the projecting end portions of the foot abutting the under edge faces of the ioists.

It is clear from an inspection of Figs. 2, 3 and 4 that only a very narrow space is required for the mechanism at each side ot the stair, 'especially when the strip members are o! sheet metal, and that they can be of such thickness as to be 'made of wood without very much increase of the width ot those spaces. l l

The parts areiirmly held in use position by gravity because when they are in that position the weight of the door assembly is sustained' largely by its hinges 29, with only a small torque force sustained by the actuating levers Il, and

by gravity because when they are in that position .the actuating bars 34 sustain a greater part of the weight oi the door assembly, with only about half of the weight'ot the stair sustained by the bars at their other ends, and with no mechanical advantage for either-other than the difference in the lengths of the lever arms, which isv not a This over-center eiiect can be had throughout a wide range of relative dimensions and relative weights of parts, without changing the leverage position or size oi.' the counterweight. Correspondingly, the assembly does not involve any difilcult balancing problem.

A longer range of movement of the upper end of the stair can be provided by using` a shorter stair or increasing the length oi the toggle arms. or by doing both. The structure is such that the device can be operated from either the upper iioor or the lower :door even when the parts are so proportioned that the angle between the-links 26 and the upper end portion of the st'air is substantially less than a right-angle.

Various modifications are possible without sacriiice of all of the advantages set forth in the above statement of objects and without departure from the scope of the appended claims.

I claim:

l. The combination of a'stair having movingpivot mounting means at its upper end, a link having a iixed axis at one end and pivoted to the stair at its oth'er end, a hand rail pivoted on the said fixed axis, and asecond link connecting the hand-rail with the stair, the hand-rail, the two links and the stair constituting a parallel-motion.

2. A stairway assembly comprising a pair of horizontally disposed, spaced-apart, side members, a door supported by' said members and having a stair-opening between them, runway means disposed at least approximately lengthwise of, and on the inner face of, said members, a stair,

runner means on the upper end portion of the stair for coaction with said runway means, and

a link having one of its axes xed with relation to one of said side members and its other axis vfixed with relation to the stair.

3. A stairway assembly comprising a door structure having a stair-opening therein, at least approximately horizontal runway means mounted in xed relation to and below the upper face of said. iioor structure, a full-length, rigid stair,-

runner means on the upper end portionvoi the stair for coaction with said runway means, the runway means and the runner means constituting a moving-pivot connection about which the stair l can beswung upward to stored position and downvin an atleast approximately horizontal position,

the assembly including a hand-rail and means so connecting it to the -iioor structure and 'to the stair as to cause it to lie close to and atleast approximately parallel to the stair when the latter also becausevth'e weight of the stair has a substantial mechanical advantage byv reason of the angular relation of the guide rails il and the levers Il..

'I'he parts are strongly held in stored position is in stored position and to be brought to useposition by swinging of the stair to use position.

` 4. A stairway assembly comprising a tloor struc-l j ture having a stain-opening therein, at least approximately horizontal runwaymeans mounted in ilxed relation to and below the upper face ot n said door structure. a fun-length. rigid stair,

runner means on the upper end portion of the stair for coactlon with said runway means, the runway means andthe runner,` means constituting a moving-pivot connection about which the stair can be swung upward to stored position and downward to use position, and means for stopping the stair in use position, the dimensions and positions oi.' the recited elements being such that when in use position and also when in stored position the stair iswholly below the upper face of said iioor structure and wholly within its horizontal limits and, when in stored position, is wholly disposed in an at least approximately horizontal position, the combination including a, trap-door hinged to the floor structure for closing the stair opening, runway means on the trap-door, runway means on the stair, a lever fulcrumed on an axis fixed with relation to the floor structure, and runner means on respective arms o! the lever for coasting with the last mentioned two runway means respectively.

5. A stairway assembly comprising a floor strucvture having a stair-opening therein, at least approximately horizontal runway means mounted in fixed relation to and below the upper face of said floor structure, a "full-length rigid stair, runner means on the upper end portion of the ward to use position, and means for stopping the' stair in use position, the dimensions and positions of the recited elements being such that when in use position and also when in stored position the stair isv wholly below the upper face of said iloor structure and wholly within Aits horizontal limits and, when in stored position, is wholly disposed in an at least approximately horizontal position, the combination including a trap-door hinged to the floor structure for lclosing the stair opening, and means so connecting the stair and the trapdoor that movement of one of them toward vertical position and toward horizontalV position effects corresponding movement of the other.

6. A ladder assembly comprising a supporting structure having at least approximately horizontal runway means thereon, a ladder having at one end runner means hingedly associated with said runway means, and a link having one of its axes xed with relation to said supporting structure and its other axis iixed with relation to the ladder,

WIILARD D. EAKIN.