US2101659A

US2101659A - Fire escape

Info

Publication number: US2101659A
Application number: US97933A
Authority: US
Inventors: Vale Baldwin
Original assignee: Individual
Current assignee: Individual
Priority date: 1936-08-26
Filing date: 1936-08-26
Publication date: 1937-12-07
Anticipated expiration: 1954-12-07

Description

Dec, 1, 1937. B. VALE 2,101 6 9 FIRE ESCAPE Filed Aug. 26, 1936 3 Sheets-Sheet 1 FIG. 2. I W

FIG. I

-|NVENTORI Dec. 7, 1937. B. vAL

FIRE ESCAPE Filed Aug. 26, 1936 3 Sheets-Sheet 2 FIG; 3.

IN VENTO R:

B. VALE FIRE ESCAPE Dec. 7, 1937.

Filed Aug. 26, 1936 3 Sheets-Sheet 3 FIG. 5.

Patented Dec. 7, 1937 V s f- UNITED STATES PAT-E This invention relates to improvements in fire escapes and more particularly to automatic extension stairs therefor.

- Among the objects of the invention is to provide' an inclined stair extension applicable to the conventional fire escapes, which maybe normally suspended in a vertical position and automatically lowered 'into inclined relation to the ground and the first balcony.

'Another object is to provide a fire escape extension stair which conforms to the regulations 'governingsuch structures, that is strong, simple, free fromsmall and intricate parts subject to climaticdeterioration and mechanical failure at 1 critical moments. a l h Another object is to 'd' celerate the descent of the stair into operative position; Anotherobject is to avoid the danger of injury to sidewalks and pedestrians in lowering the stairs.

.Afurther object is to divert the stair during its vertical descent to the inclined operative position just prior to the end of the descent.

Other objects and advantages will appear as 25. the description progresses.

- In this specification andthe accompanying drawings the invention is disclosed in its application to a conventional condition. However, it is to be understood that it is not limited to this form because it may be embodied in other forms within the purview of the claims following the description; W

- i In the three sheets of drawings:

[is a side elevation of a fire escape having an extension stair constructed and combined therewith in accordance with this invention. The extension is shown in the operative position. Fig. 2 is a front elevation of the same, with the extension raised into inoperative position.

Thehand rail has been omitted in this view.

Fig. 3 is an enlarged detail in side elevation of the upper portion of the installation, showing the hoisting and suspension assembly with the head of the extension stair in the inoperative position. i

Fig. 4'is an end elevation of the same showing the windlass locking pawl in the operativeposi tion. The head of the stair has been omitted in this figure;

Fig. 5 read in conjunction with Fig. 4, shows the head of the stair in operative relation to the lower balcony bracket.

In detail the structure illustrated in the drawings referring first to Fig. 2, comprises the con-- .55 ventional balcony platforms l and 2 rigidly fixed to the building wall 3 and having the enclosing railings such as 4 and 5, respectively. The balconies are usually constructed of conventional steel shapes, with various architectural modifications in design. a

The interspaced standards 6 and i are bolted at 8 and 9 to the upper platform I and fastened to the top rail 4 by clamps such as l0, see Figs. 1 and 4. The U shape Windlass yoke, see Fig. 3,

has the cross plate, ll fixed to the standards 6 10' and l by the upper ends of the guide rods I2 and I3 between the nuts l4, l5 andlB, I1 respec' tively. The front extensions of the clamp l0 are also interposed betweenthe standards 6, l and the plate II, the whole assembly being, drawn 15 tight between the respective nuts l4l'|, see

Fig.3.

The upward side extension. l8 of the yoke has the bearing IQ for the trunnion 29 on the windlass head 2i. The opposite extension 22 has the 20 square thimble 23 forced snugly through a square hole therein to provide a non-turning anchorage for the shaft 24 fixed therein by the transverse taper pin 25.

The opposite head 26 of the windlass has the 25 stuifing box 21 encircling the shaft 24 upon which it revolvesfreely. The Windlass comprises the cylinder 28, fixed within the opposed heads 2! and 26 to' forma pressure-tight cylinder freely 'revolvable on the trunnion 20 and'the shaft 24 30 between the yoke sides l8and 22 g The head 26 has the spur gear 29 thereon enmeshed with the pinion 30 fixed by the pin 3i on the crank shaft 32, extending through the yoke sides I8, 22 and terminating in the hand 5 crank 33. The pinion has the flange 34 bearing against the side of the gear 29 under the pressure exerted by the spring '35 when the gear and the pinion areenmeshed for rotating the Windlass. The pinion3ii can be disengaged from 42 the gear 29 by sliding the shaft 32 longitudinally and inserting a. pin through the hole 36 when it is beyond the yoke side 22. This is a precautionary measure to prevent the crank 33 revolving during the unwinding of the Windlass and strik-' 45 ing an occupant of the upper balcony.

.To prevent the unwinding of the Windlass the pawl 31 is provided, see Fig. 4. This pawl has .the pin 38' pivoted in the

bearings

39, 40 formed in theplate 4|, held beneath the nut 14. This 50 pawl has the

teeth

42, 43 thereon adapted to mesh with the teeth on the gear 29. The pull' wire 44 depending from the end of the pawl, extends through the grating of the upper platform and V has. the handle 45 attached thereto within easy 7 N OFFICE reach of an adult person on the lower platform 2. It is also advisable that it extend below the lower platform 2 and terminate in the ring 46 within reach of a firemans hook.

The vertical guide rods l2, l3 extend downward and through the lower bracket 47, bolted at 48 to the lower platform I, see Fig. 5. This bracket has the forward extension 49 through which the rods l2, I3 pass and to which they are firmly fixed by the nuts 50, El and 52, 53 respectively. The bracket is slit adjacent each end and the center portion 54 curved downward to form a fulcrum for the extension stair.

Referring to Fig. 2 this stair comprises the

side stiles

55, 56 joined by the threads 51 at proper intervals. The length of this extension stair is equal to the distance from the first platform I to the ground at the usual stair inclination. The upper ends of the stiles are bent outward to form the

angular heads

58, 59 respectively. The respective rods l2 and l3 pass through enlarged openings in these heads to guide the descent of the stair.

The hoisting cable has its center portion or bight 68 passed through the staple 6| butt welded to the periphery of the Windlass cylinder 28, see Fig. 3. The cable length equal to the descent of the stair is wound around the Windlass in opposite directions until its

opposite extensions

62, 63 descend between the standards 6, l and are fixed in their

respective heads

58, 59 as at 64, 65. The whole weight of the extension stair is thus suspended by the

cable ends

62, 63 and the Windlass which is locked by the pawl'3'l.

The pawl is so arrangedthat the Windlass gear 29 must be advanced one tooth by the swing of the pawl on its center 38, so that the weight of the stair suspended thereby must be lifted before the

teeth

42, 43 disengage and release the windlass.

When the Windlass is thus released the weight of the suspended stair rotates the Windlass to unwind the cable. The stair is guided in its descent by the vertical guide rods l2, l3; the equalized tension of the cable ends-62, 63; and by the

extensions

66, 61 of. the plate 49 lateral to the fulcrum '54. a

This fulcrum being lateral to the longitudinal center of the width of the

side stiles

55, 56, which are centered on the guide rods, causes a cramping action when the stair approaches the end of its descent, see Fig. 5. This causes the lower end of the stair to swing outward to the desired inclination before coming to rest upon the ground. This feature of the operation is meritorious because the path of descent of the stair is often restricted by awnings, signs and architectural projections from the wall 3. It has the further advantage that the end of the stair cannot break through the side walk nor guillotine a pedestrian, since the out swing occurs relatively close to the ground. The progressive angle of the outswing increases the friction against the fulcrum 54 tending to retard the descent in addition to the decelerating effect of a change of direction.

Since such extension stairs weigh about six hundred pounds, more or less according to length, it is necessary to decelerate their descent. In the present instance this is accomplished by liquid displacement, see Fig. 3.

The threaded portion 68 of the shaft 24 engages the running nut 69 forming the hub of a piston of any desired construction, such as the cup leather 1c clamped between the flange H of the hub and the disk E2. The threaded portion 68 .of

the shaft 2t is held stationary as previously described and has its end 13 journaled in the step bearing 14 in the head 2l.

To cause the piston assembly to revolve with the cylinder-Windlass 28, the rod 15 extends between and engages sockets in the cylinder heads 2!, 26, respectively, and passes through the piston parallel with the shaft 24. As the Windlass revolves to lower the stair, the rod 15 causes the piston to revolve and advance along the thread 68 toward the head 21, displacing the oil 16 which slowly leaks between the threads 68 and where the rod passes through the piston. The oil being noncompressible, the slow leakage decelerates the rotation of the Windlass and the descent of the stair. The rate of liquid displacement depends upon the fit of the threads, or a calibrated opening can be provided through the piston to speed up the descent. About one inch of piston travel to each foot of descent is good general practice, to accomplish a speed of about two feet per second of descent. Different ratios are available by changing the pitch of the thread 68'or varying the displacement through the piston. The same variations in descent speed-can be also accomplished by varying the viscosity of the oil 16. While oil is preferred, a dry disk brake applied by an. appropriately pitched thread 68 could be substituted for the oil displacing piston, for efiecting a progressively applied frictional deceleration. While they are both equivalent friction means, the oil system is preferable sincethe oil will continue to flow until the stair comes to rest.

The liquid displaced in descent is impounded between the piston and the stuffing box 21. All Working parts within the cylinder-Windlass are lubricated by the oil 16.

In freezing climates it is advisable to leave an air space within the cylinder by not filling it completely with oil at the plug Tl. Should the guide rods l2, [3 become ice encrusted the air space within the cylinder 28 will permit the stair to drop a foot or so before the deceleration takes effect, this will cause the stair heads 58,

59 to jar the rods l2, l3 and shear off the ice during the remainder of the descent. Under such conditions it is advisable to enclose the hoisting mechanism including the head of the stair in an enclosing hood 18, as in Fig. 5.

The guide rods l2, I3 join the two platforms 1,

2 to distribute the load between them.

This invention operates substantially as follows: The pin is removed from the hole 36 permitting the spring 35 to slide the pinion 30 into mesh withv the gear 29, see Fig. 3. The stair is then hoisted by turning the crank 33 to wind the cable up on the Windlass 28. The operator holds the pawl 37 up in readiness to engage the gear 28 at the top of the lift. With the pawl securely holding the Windlass, the shaft 32 is slid to inoperative position and held by a pin through the hole 36. During the ascent of the ladder the travel of the piston is reversed on the thread 68, restoring the oil impounded behind the piston to the chamber in front of the piston. Since a cup til with appropriate modifications, is equally applicable to many, other uses such as ships" ladders, life boat and various other hoists.

Having thus described this invention, what is claimed and desired to be secured by Letters Patent is: V p

1. In combination with the upper and lower platforms of a fire escape; a pair of rigid guides terminating in a lower bracket having a fulcrum forward of said guides; a vertically movable stair engaging said guides and slidable on said fulcrum.

2. In combination with the upper and lower platforms of a fire escape; a pairof rigid guide rods extending between said platforms; a fulcrum on said lower'platform forward of said guides; a stair having its head engaging said 'rods and its rear edge slidable on said fulcrum.

.3. In combination with theupper and lower platforms of a fire escape; rigid guiding means extending between said platforms; a fulcrum on