Ladderless safety escape device

A ladderless safety escape device includes a cable drum upon which a cable is wound having means secured to the free end thereof for the support of a person. A braking mechanism is operatively connected to the cable drum for controlling the rate of descent of the person. A brake control mechanism is provided for operatively disconnecting the brake mechanism from the cable drum during rewinding of the cable and insures operative connection of the brake mechanism and cable drum during unwinding of the cable.

BACKGROUND OF THE INVENTION 
The present invention relates to fire escape devices and more particularly 
to a ladderless safety escape device including a cable drum and brake 
mechanism therefor. 
Ladderless safety escape devices of the character described have been known 
heretofore. The brake mechanism is an extremely important component of 
such devices. As might be expected, confidence in devices of this type 
depends to a large extent upon the reliability of the braking system and 
upon the safeguards provided to insure against the inadvertent 
uncontrolled descent of the person being lowered to safety. It is also a 
safety factor in insuring that the cable drum is locked against accidental 
unwinding of the cable from the drum before the person is properly secured 
in the seat or chair. Prior devices did not provide mechanism which were 
sufficiently reliable in these respects so as to stimulate the degree of 
confidence in such safety escape devices as is necessary for their 
widespread acceptance by the general public. 
SUMMARY OF THE INVENTION 
It is one object of this invention to provide a ladder-less safety escape 
device whereby a person may be lowered to safety from an elevated level of 
a building at a controlled rate of descent and which includes brake 
control mechanism which automatically prevents unwinding of the cable 
unless the brake mechanism is operatively connected to the drum. 
It is another object of this invention to provide a ladderless safety 
escape device for lowering a person to safety from an elevated level of a 
building at a controlled rate of descent and which includes mechanism for 
locking the cable drum against accidental unwinding of the cable and for 
manual release by the person to be lowered after he has been secured 
preperly in the lowering support seat. 
Other objects and advantages of the invention will become readily apparent 
from the following description of the invention. 
Accordng to the present invention there is provided a ladderless safety 
escape device comprising in combination: a frame; a cable drum mounted 
rotatably in the frame; a cable wound upon the drum and having means 
secured to the free end thereof for the support of a person; a braking 
mechanism for the drum mounted concentrically about a portion thereof for 
controlling the rate at which the cable is unwound to thereby regulate the 
rate of descent of the person; a brake control mechanism adapted to 
selectively operatively connect and disconnect the braking mechanism and 
the cable drum, including means for automatically connecting the braking 
mechanism and cable drum in the event the cable drum begins to unwind 
without being operatively connected to the braking mechanism; manually 
operable cable drum control means for selectively locking the drum against 
rotation; and a rewind handle connected to the cable drum for rewinding of 
the cable thereon.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to the drawings there is shown generally a ladderless safety 
escape device 10 which can be mounted by any suitable means preferably on 
the outside of a building in the immediate vicinity of a window for 
convenient availability to persons occupying an upper story of the 
building. 
The escape device comprises a cable drum 12 mounted rotatably in frame 14 
only a portion of which is shown. It will be understood that standard 
channel or equivalent structural members may be welded or otherwise 
securely joined to the main body of the frame so that the escape device 
can be installed on the side of a building. Alternatively the entire unit 
may be enclosed within a housing and stored inside the building beneath a 
window. 
It will be understood, of course, that in referring to the use of a cable 
drum it is contemplated that a flanged pulley may be employed or a cable 
shaft one end of which may be provided with a brake mechanism to be 
described hereafter. A rewind handle 15 is secured to the brake end of the 
drum for rewinding the cable thereon after someone has been lowered to 
safety and in preparation for the lowering of the next person. 
A cable 16 is wound upon the drum and has its free end connected to a 
support structure 18, which desirably includes a seat element 20 and a 
safety belt 22, for supporting a person to be lowered to safety from the 
building. Although the term cable is used throughout the specification and 
in the appended claims it will be appreciated that this term has been 
employed in its generic sense and includes ropes and wire elements whether 
formed of natural or synthetic fibers or of metal. 
A braking mechanism 24 is mounted concentrically about the cable drum or an 
extension of the shaft thereof and may incude a brake drum 26, and brake 
lining 28 and brake band 30. It wll be observed that the brake lining and 
brake band do not extend completely about the cable drum, the brake lining 
being split as illustrated in FIG. 2 and the brake band having its 
circumferential end portions 32, 34 extending in a generally radial 
direction and in spaced relation. A spring 36, desirably a coiled 
compression spring, is mounted so as to normally bias the brake band to 
exert a radially directed braking force through the brake elements on the 
cable drum or its shaft. In this manner a sufficient braking force is 
applied to the drum so as to afford a regulated rate at which the cable is 
unwound and at which the person is lowered. Such rate of descent may be 
varied by adjusting the spring tension in a known manner such as through 
the tightening of a nut 38. 
A brake control mechanism is indicated generally as 40. The purpose of this 
control mechanism is to provide a safety against accidental release of the 
cable drum when the brake is not in operative connection therewith. The 
control mechanism includes a brake cam 42 mounted fixedly upon a shaft 44. 
The cam is positioned between the spaced brake band ends and is pivotable 
between a first position in which such ends are urged apart by the cam 
against the bias of spring 36 to thereby remove the braking force from the 
cable drum and a second position out of engagement with such ends. In the 
second position the spring 36 is free to bias the ends towards each other 
and apply a braking force to the cable drum or to the brake drum which 
constitutes an extension of the cable drum. 
The shaft 44 is journaled in the frame and carries at its upper end a lever 
member having first and second sections 46, 48. Section 46 surmounts the 
shaft and section 48 extends outwardly therefrom a sufficient distance so 
as to project into the rotational path of rewind handle 15 when the lever 
has been shifted clockwise 90.degree. from the position shown in FIG. 3. 
Alternatively the lever sections may comprise coperable components of a 
ratchet (not shown) by means of which one of such sections is pivotable 
relative to the other and is positionable, when the brake control 
mechanism is disconnected as depicted by broken line in FIG. 3, within the 
path of rotation of rewind handle 15 constructions are well known and the 
present specification will not be unnecessarily encumbered with a detailed 
description in this respect. Suffice to state that the lever sections 46, 
48 and stud so are so arranged as to enable one to move cam 42 into either 
of its first or second positions by means of stud 50. Thus, with the brake 
cam 42 pivoted into its first position as shown by broken line in FIG. 3 
the ratchet lever 48 is shifted into the path of rotation of rewind handle 
15. During the rewinding of the cable drum lever 48 is pivotable relative 
to lever section 46. Once rewinding of the cable has been completed one 
should pivot the cam into its second position by means of stud 50 so that 
the braking mechanism is once again operativey connected to the cable 
drum. However, in the event that this is inadvertantly not done the lever 
arrangement serves as an automatic safety device. In such event as soon as 
the cable begins to unwind the handle 15 will engage with lever section 48 
which is in the path of rotation of the handle. The striking of the lever 
section 48 by handle 15 will cause the lever to shift the substantially 
90.degree. so that cam 42 is moved into its second position as shown in 
FIG. 2 out of contact with the spaced ends of the brake band thus 
permitting spring 36 to apply a braking force to the cable drum. 
In order that the person to be lowered may directly control the release of 
the cable drum a quick release mechanism is provided. Thus, a stationary 
element 52 is secured to the frame 14 as by welding. A link or arm 54 is 
pivotably mounted on element 52 as by means of a pivot pin 55. Apertures 
56, 58 are formed in stationary element 52 and in link 54 is aligned 
relation. A pin 60 is dimensioned to fit snugly within the aligned 
apertures, and in such condition the link element 54 extends into the path 
of rotation of handle 15 and prevents rotation of the cable drum. In this 
state the cable cannot be unwound. Once the person is loaded and properly 
secured in seat 20 the pin can be pulled out of the apertures by means of 
handle 62 which is connected to the pin by chain 64. The cable will then 
unwind from the drum and the person will be lowered at a controlled rate 
of descent since the cable drum will unwind under the influence of the 
braking mechanism hereinbefore discussed. To facilitate reception and 
retention of the pin 60 within the aligned apertures the pin may be 
tapered. As will be observed in FIGS. 1 and 3 a spring 66 may be provided 
to retain the pin and handle assembly while the person is being lowered. 
From the foregoing it will be seen that a safety escape device has been 
provided which is operative without the need for a ladder and which 
provides for an automatic control of the braking mechanism so that there 
is no danger of accidental release of the drum at any time without the 
influence of the braking mechanism. Thus, the drum will only spend cable 
therefrom at a controlled rate. Also, the quick release mechanism insures 
that manual control of the cable drum is afforded. The person to be 
lowered can, in the manner described, determine exactly when his 
controlled rate of descent should commence. This combination of features 
should impart to ladderless escape devices a degree of public acceptance 
not enjoyed heretofore.