US 2314004 A
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March 16, 194 R. B. MARSCHKE 2,314,004
FOLDING STAIRWAY "Original Filed Aug. 19, 1940 2 Sheets-Sheet l March 16,1943. R. B. MARSCHKE 2,314,004
FOLDING STAIRWAY Original Filed Aug. 19, 1940 2" Sheets'Shee 2 Zlyvuwwbo'r REINHOLD B. MARSCHKE Patented Mar. 16, 1943 UNITED STATES PATENT OFFICE FOLDING STAIRWAY Reinhold B. Marschke, St. Paul, Minn.
Original application August 19, 1940, Serial No. 353,164. Divided and this application December 18, 1941, Serial No. 423,474
Claims. This invention relates to folding stairways which include a substantially rectangular frame and are provided with a stairway section in said frame.
one section of the stairway will fold against the The stairway is made sectional so that other section topermit the stairway to be folded into a compact state so that it will fit within the rectangular frame in the ceiling of a building. -The stairway sections are adapted to be extended in a manner to form a continuous stairway from one floor to another in a building.
This application is a division of application filed August 19, 1940, Serial No. 353,164, for Folding Stairways.
It is a feature to provide a unitary structure which includes the rectangular casing, the foldable stair sections and the lever and spring means adapted to cause the stair sections to fold in a-compact state and when folded to lie within the rectangular frame which holds the stairway together as a unit. Thus my stairway may be made up in a unit structure, completed at the factory where it is manufactured, and shipped to the customer in complete form so that all that is necessary to install the same is to pro- -vide an opening between the floors where the stairway is to operate and in the ceiling of the building, and then by securing the rectangular frame in position in said opening, the stairway will be ready for use.
It is also a feature to provide a foldable stairway having a series of sections, one section of which is secured at one end to the frame which surrounds and holds the stairway when it is folded, and to provide a pair of levers pivotally secured at one end to the frame and at the other end pivotally and slidably secured to the stairway section. I also provide a pair of arms pivotally secured to the levers and pivotally connected to a spring urged arm means which rotates in a manner to wrap the spring thereabout,
increasing the tension of the spring when the stairway is extended and rotating in the opposite direction when the stairway is closed, thus providing the increased spring tension for lifting the stairway when it is extended and decreasing the spring tension when the stairway is in folded position and stored out of the way in the rectangular frame.
These features together with other details and objects will be more fully and clearly hereinafter set forth.
The drawings illustrate in Figure 1 the rectangular unitary frame with the foldable stairway enclosed within the frame. showing the same in perspective looking up toward the bottom and closure of the stair unit.
showing the side operating leversand spring and showing the stair sections extended'in full open position.
Figure! is a detail of a portion of the stair sections in closed position; and showing the balancing levers with the cam head secured thereto and the spring operating in conjunction with the levers and the cam head.
Figure 8 is a similar detail to Figure 7, showing the parts in partially opened position and illustrating the manner in which the spring wraps around the cam head as the cam head moves from closed toward open position.-
Figure 9 is a similar detail to Figures 7 and 8, showing the balancing lovers, the spring, and the cam head in the approximate position of the same when the stair sections are in full open or in practically full open position.
In my unitary folding stairway I provide a rectangular casing In which encloses the stairway A when the same is folded and the bottom cover I! is in closed position as illustrated in Figure 1.
My stairway A is made up in complete form with the rectangular casing 10 which is adapted to support the folding sections l2 and 13 of the stairway within the same; When the stairway isfolded the. closure l.l acts to close or conceal the stairway sections J2 and I3 from below. The cover Il may act as a ceiling closure when the casing I0 is positioned within a rectangular opening formed in the ceiling of the building and the casing I9 is secured in position to hold the stairwayA in place in said opening.
The section 1.2 of the stairway A carries the cover or closure l I along the bottom of this stairway section and the upper end of this section is pivotally secured at I 4 on each side to the casing l0.
The folding stair A has its bottom section 13 Coil springs I9 engage the free end of the levers l6 and these springs extend under the rollers which hold the coil spring extending: under the treads of the stair section 12. The coil springs l9 extend on either side of the respective sections 12 and I3 and when the sections are extended the lower section l3 locks by means of the shoulder 22 in the notch 23 to provide with the levers IS the necessary rigidity to hold the lower section l3 extending from the upper section 12 as illustrated in Figure 3.
By pulling on the lower section i3 and removing the shoulder 22 from the notch 23, the arms l6 and springs IE will act to pull the stairway section l3 up into folding position.
Balancing levers 25 and 26 are provided for the folding stairway A, the levers 25 and 26 being pivoted together at 21 and the levers 25 being pivoted to the sides of the casing I0 at. 28 on one end. The other ends of the levers 2.5 are pivotally and slidably connected by means of the rollers 29 which roll in the longitudinal tracks 30 secured to the stringers of the section l2 of the stairway.
The lever 25 has one end pivotally connected at 31 to the arm 32, which arm is rigidly secured to a cam block 33. The arm 32 is pivotally connected at 34 to the side of the casing l0. Balancing coil springs 35 have one end attached at 36 to the cam block 33 and lever 32, while the other end of these coil springs 35 are connected to the casing l0, not shown. Thus when the stairway is moved into folded position the cam block 33 and the levers 25 and 26 will be in the position illustrated in Figure 7. It will be noted that the pivot point 3| extends slightly to the left of the pivot point 34 so that when it is desired to open the stairway A, the hook 31 which is secured to the cover II as illustrated in Figure 1, is engaged and with the downward pull on the cover I I, the cams 33 are caused to rotate on the pivot point 34, winding one end of the spring 35 around the same to automatically increase the spring tension as the stairway A opens up, and thus providing a balancing spring cam and lever means for operating the stair to permit the same to be easily lifted into closed position.
It will be apparent that any style of section l3 may be attached to the section 12 of my folding stairway so that the section l3 may be secured to the section l2 in any suitable manner which permits the section l3 to fold up onto the section l2 before the section I2 is lifted by the levers, cam and spring means into closed position. It will also be apparent that a tension remains on the cam 33 by reason of the spring 35 to hold the cover H closed under spring tension.
The easy operation of my stairway together with its unitary structure and the simple cam, lever and spring means which provide a balancing means for my stairway, permit me to make my stairways in an economical manner, yet they are strong and durable to provide a stairway in the attic of a building, or from one floor to the other, all of which is concealed when the stairway is closed. In a stairway of this character it is of primary importance that the same be made economically so that people can afford to use the same in buildings and homes where they are required.
In accordance with the patent statutes I have described the principles of my stairway, together with the details of construction thereof, and I desire the patent to be interpreted within the scope of the following claims or the equivalents thereof.
1. A folding stairway including a rectangular frame for enclosing the same, stairway sections pivotally secured at one end to said frame and connected together in a manner to fold into a compact state within said rectangular frame, a pair of levers pivotally secured at one end to said frame and at the other end pivotally and slidably secured to said stairway section, a pair of arms pivotally secured atv one end to said levers and pivotally Secured at the other end to a pair of cam levers, said cam levers pivotally connected to said frame, a cam member on each of said cam levers, spring means for urging said cams to rotate said levers in one direction by the tension of said spring, means, whereby as said stairway is opened, the tension on said spring means will increase to provide a balancing operating means for said stairway.
2. A folding stairway including stairway sections pivotally and slidably connected together, a rectangular frame for receiving said stair sections when they are folded, a closure secured to one. of said sections to close said stairway from below when folded, a pair of levers pivotally and slidably secured to the sides of saidupper stair sections and pivoted to the insides of said rectangular frame, a pair of links pivotally connected atone end to said levers and pivotally connected at the opposite end to a pairof cam arms, cam members rigidly secured to said cam arms, said cam arms pivotally secured to said frame, coil springs adapted to wrap around said cam members as the stairway sections are opened, and to unwrap from said cam members when the stairway sections are closed to provide a spring and lever balancing; means for said stairway in the operation of the same.
3. A unitary foldable stairway in combination with a casing for enclosing and supporting the same, comprising an upper stair-way section having one end pivoted to said casing, a pair of balancing levers on either side of said upper stairway section having one end slidably and pivotally connected thereto, pivot means for attaching said pair of levers inside of said casing, said balancing pair of levers including a secondary lever pivoted at one point between the ends of the levers which are slidably connected to the upper stairway section and having the other end of said pair of levers pivotally connected to a pair of cam arms, means for pivoting said cam arms to said casing, a cam member on said cam arm, and a balancing spring adapted to be wrapped and unwrapped around said cam in the operation of said stairway to provide a spring balancing means for said foldable stairway.
4. A folding stairway comprising a substantially rectangular frame, a stairway section pivotally secured at one end to said frame, a pair of levers pivotally secured at one end to said frame and at the other end pivotally and slidably secured to said stairway section, a pair of arms pivotally secured to said levers at one end' ed to be wrapped and unwrapped around each of said cam members in the operation of said stairway to provide a spring balancing means for said folding stairway.
5. A sectional stairway for buildings including a substantially rectangular casing for enclosing said stairway when it is folded, foldable stair sections, means for pivotally and slidably supporting one of said sections in relation to the other of said sections, the other of said sections being adapted to support a closure on the bottom thereof which acts to conceal the stairway when it is folded, and said otherlfsection being adapted to be pivotally connectedon one end to said rectangular casing and being sildably and pivotally connected to a pair of balancing lever means which are pivoted to said "casing, a pair of links pivoted to said balancing levrs at one end thereof and pivoted at the otherfend to a. pair of cam arms, said cam arms beingpivoted to said casing, a cam member secured rigidly to each of said cam arms, and a pair of coil springs adapted to wrap around each of said cam members to increase the tension on said springsf when sections of said stairway are extended intdtopen position.
REINHOLD B. MARSCHKE.