US2577914A - Disappearing stairway - Google Patents

Description

-Dec. 11, 1951 w. c. PFAHL 2,577,914

DISAPPEARING STAIRWAY Filed June 1, 1946 4 Sheets-Sheet 1 INVENTOR. .Wi/berf L'P/a/zl Dec. 11, 1951 w. c. PFAHL 2,577,914

DISAPPEARING STAIRWAY Filed June 1, 1946 4 Sheets-Sheet 2 250 INVENTOR.

WzYberHTP/"a/zl BY WW4 Dec. 11, 1951 w. c. PFAHL 2,577,914

DISAPPEARING STAIRWAY Filed June 1, 1946 4 Sheets-Sheet 3 Jig-5M 27v 37 26a.

IN VEN TOR.

ByWflberM'PfafzZ 2 r 63 Dec. 11, 1951 w. c. PFAHL 2,577,914

DISAPPEARING STAIRWAY Filed June 1, 1946 4 Sheets-Sheet 4 INVENTOR. WILBERT C. PFAHL BY I ATTORNEY Patented Dec. 11, 1951- UNITED STATES PATENT OFFICE 7 2,517,914 DISAPPEARING STAIRWAY Wilbert C. Pfalil, Silver Lake, Ohio Application June 1, 1946, Serial No. 673,795

2 Claims. 1

This invention relates to disappearing stairways of the ceiling or overhead iioor type.

Heretofore, stairways of this type have been manufactured in which a panel was hinged at one end of an overhead floor openin with a stair structure extensibly and retractibly mounted on the panel, and with spring-wound drums and cables provided for separately counter-balancing the panel and stair structure. Greatdiiiieulty has been encountered in the past, howeven-"in that when the spring drums became outof order the customer could not remove the same without substantially completely dismounting the entire stairway structure, which then remained out of service while repairs were being made. Another serious difiiculty arose in that the customer usu-i ally possessed insuflicient skill or equipment for setting requisite counter-balancing tensions in the drums.

One object of the invention is to provide apparatus of the character described including improved means for effectively mounting springwound counter-balancing drums, which may be easily removed for repairs, adjustments or replacements. without disturbing the manual operation of the stairway.

Another object of the invention is toprovide in ap aratus of the character described, im-. proved spring-drum mountings adapted to be supplied in separate removable units, with the spring drums therein set with requisite tensions and ready for attachment of the operating'c'ables thereof, whereby no special skill or equipment is required to detach or assemble the spring-drums in the apparatus.

Other objects of the invention will be manifest from the following brief descriptionand the accompanyin drawings.

Of the accompanying drawings:

Figure 1 is a top plan view, partly broken away, illustratin a disappearing stairway embodying the features of the invention.

Figure 2 is a vertical cross-section through the apparatus, taken substantially on the line 2-2 of Figure 1.

Figure 3 is a fragmentary top plan view, on an enlarged scale, taken at the left of Figure 1.

Figure 4 is a cross-section, on the same scale,

taken on the line 4-4 of Figure 3.

\ j Eigure5 is a s milar crossesection taken on the line 5-1-5'of Figure 3. a j f'li'igure 6 is an enlarged top plan view, showing the apparatus in dismounted condition.

Figure 7 is an enlarged side elevation of the apparatus in dismounted condition.

Referring to the drawings, the humeral I designates an-overhead floor structure, having therein a rectangular opening II at one end of which is hinged a closure panel I2. Secured to one end jamb of opening II, above the hinge point'of the panel, is a bracket I3 having thereon spaced inwardly proiecting lugs I4, I4, on which is pivoted a frame I5 including opposite elongated guide strips I6, I6, for sliding engagement in opposite guide slots I1, I! along the outer faces of stringers I8, I8 of stair structure I9. Adjacent the free end of panel I2, at opposite sides thereof, is mounted a pair of lugs 20, 2|] on which elongated guide blocks 2 I 2I are pivoted to be slidable in said guide slots I'I. Thus, the stair structure I9 is slidable on the guide strips I6 and guide blocks 2I, toward and from a retracted position (not shown) upwardly through opening II. Releasable latching devices of known type, are provided at the lower ends of the stringers, as indicated at 22, and on the lugs 20, for releasably locking the stairway when moved toward retracted position. By means of the equipment so far described the stairway is manually operable toward and. from said retracted position thereof.

For facilitating effortless operation of the stairway toward and from retracted position, removable and replaceable spring-winding units 23, 23 may be provided at each side of the opening II, in spaces provided between the o posite stringers I8 and adjacent side jambs 24, 24. The units 23 may include L-shaped brackets each having side and end plates or legs 25 and 26 for suitable releasable attachment as by means of screws, against the corresponding side and end jamb faces at the hinge end corners of openin I I. To provide additional rigid support for the units angular lug extensions 25a and 26a are provided on the side and end plates thereof for attachment, as by means of screws, to the upper floor surface. Integral with the side plate 25 of each unit 23 may be horizontally spaced, open-ended tubular stems 2'! and 28, extending free y laterally inwardly and being received through central apertures of panel and stairway counter-balancing spring drums 29 and 30, respectively. The drums are hollow, and have flat springs 3I and 32, respectively, hooked at one end through slots in outer cable-winding peripheral portions of the drums, the inner ends of the wound springs being similarly hooked through slots 33 and 34 extending from the open ends of the tubular stems 21 and 28. Cotter pins 35 and 36 prevent accidental'removal of the drums from the stems thereof.

- Attached to the winding peripheral portion of each panel counter balancing drum 29, may be a flexible cable 31. which extends over a pulley 38 (see Figure 2) attached to the side iamb 24 adjacent the other end of opening II, the other end of the cable extending downwardly and being slidably adiustably attached to suitable attaching means 40 on the panel. This sliding attachment is of knowntype adapted to facilitate operation of a stop member 4| on the cable for limiting downward pivotal movement of the panel and end of which is attached to a lug 43 on the outer' face of stringer l8 intermediate theends thereof (see Figure 2).

The springs of the drums 29 and 30 'areseti.

with desired tensions when placed on the respective stems thereof, in such a manner as to provide requisite spring tension to counter-balance the closure panel and stair-structure. This preferably is such thatin the extended position of the stairway the spring action is slightly over,- balanced ,by the weight of the stairway so that it will stay in downwardly extended condition, as best shown in Figure 2, but will require only relatively slight efiort to operate it toward retracted position. The spring tension of .the panel drums-on the other hand, is relatively weaker so that the panel will not slam closedto cause loosening of the hardware thereof.

The operation of the improved stairway structure, either with or without the spring counterbalancing means, has been clearly described above. It willbe readily seen, however, that the apparatus is adapted to be completely installed without requiring any substantially high degree of skill, and particularly with reference to assembly and attachment of the spring counter-balancing units 23. Similarly, should the counter-balancing devices require repairs or adjustments, it is only necessary to detach the extended outer ends of cables 31 and 42, remove the units with drums 29 and. 30 retained thereon, and ship the same to the manufacturer or servicing agent. When the units have been repaired or adjusted, and returned, it is only necessary to mount them in the opening ll as before and attach said extended outer ends of the cables, no spring adjustments being required by the owner or customer, because the units may be ,Iurnished with the springs properly set by means of special equipment, and with the cables properly retained in wound condition on the drums. For the last mentioned purpose, it will be readily seen by reference to Figures 6 and 7, that upon release of eachcable 31 with respect to the stair structure l9 and pulley 3.8, the stop member 4| will engage between the plate 26 and the outer peripheral portion of drum 29, thereby preventing any unwinding and also permitting presetting of the tension as previously set forth.

'It is understood that the advantages of removability and interchangeability of the units 23 may be'utilized also with single spring-winding drums thereon. Other modiflcations'of the invention may be resorted to without departing from the spirit thereof or the scope of the appended claims. I

What is claimed is: v l. A disappearing stairway for anopenin in an overhead floor structure, comprising a closure panel hinged at one end of said opening, guide ine'ans'adjacent the other end of s'aid'openin g '0'! the floor structure at opposite sides thereof, a stair structure, stair-mounting means for mounting said stair structure to be extensible and retractable on the upper side of said panel, said stair structure being'substantially narrower thansaid opening to provide spaces at opposite'sides there of, separate drum-mounting units including 4 brackets removably secured independently of said stair-mounting means to said floor structure at opposite sides of said opening adjacent the hinged end of said panel and thereby being adapted to be 'iinstalled or removed without disturbing the use of 'said stair structure as such, opposite pairs of fixed stems on each of said separate brackets, said 'stems extending from the said brackets freely I ,into said spaces at opposite sides of the stair structure, opposite pairs of spring-wound panel and stair structure counter-balancin drums rotatably ireceived on said stems of the brackets,

releasable means for retaining said drums on said stems',..fiexib1e elements connected between said opposite panel drums and said panel and guided .by said guide means for counter-balancingvsaid panel, and flexible elements connected between said opposite stair structure drums and the stair structure for counter-balancing the same. said drum-mountin units and the respective flexible elements of the drums thereof including attaching means for aflixing the flexible elements relatively :of the unit and-thereby to limit springwinding of the drums when the flexible elements are releasedfrom the respective structures onerated thereby.

2 .'=A disappearingstairway for an opening in an overhead floor structure, comprising a closure panel hinged at one end of said opening, guide means in saidfloor opening, a stair structureineluding opposite side stringers, stair-mounting means for mounting said stair structure and said panel whereby thestair structure is extensible and retractable on said panel, a separate drummounting'unit includinga bracket removably secured independently of said stair-mounting means to said floor structure at the hinged end of said panel and thereby-being adapted to be installed or removed without disturbing the use of said stair structure as such, fixed stems on said bracket extending freely outwardly thereof, separate springwound panel and stair structure counter-balancing drums, said drums being centrally apertured to be rotatably received on said fixed stems,.re-

- leasable meansfor retaining said drums on said stems, means on-said drums and on saidstems for setting predetermined spring-wound tension in the drums for aretracted position of the panel and stair structure, flexible elements connected between said panel drum and said panel and guided by said guide pulley' means for counterbalancing the panel, and flexible elements connected between said stair structure drum and the stair structure for counter-balancing the same, said drum-mountin unit and the respective flexible elements of the drums thereof including releasably interengaging portions for aifixing the flexible elements relatively of the unit and thereby to limitspring-winding of the drums when the flexible elements are released from the respective structures operated thereby.

. WILBERT C. PFAHL.

Number Name Date 1,614,006 Loetscher Jan. 11, 1927 1,636,280 Bessler July 19,1927 1,749,409 Bessler Mar. 4, 1930 2,1 3,112 ,rmzier June 20,1939

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