Note: Descriptions are shown in the official language in which they were submitted.
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`~ Description
Escalator Handrail Obstruct.ion ~;
Device With Sensors
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Technical Field
This invention relates to a safety device for use
~. on the reentry housing of an escalator handrail. More
i'i particularly, the device of this invention is operable :-~
to sense longitudinal and radial forces occurring in
the area of the reentry housing, and is further
;10 operable to turn t~le escalator off in appropriate
cases.
Background Art
The handrail on an escalator is driven over a
handrail guide in synchronism with the moving steps of
the escalator, or other moving walkway. At the exit
landing of the escalator, the handrail reverses its
direction of travel, over a curved newel in the more
modern escalators, and moves along a hidden return path : :~
of travel. The escalator handrail passes through a
reentry housing as it begins its return travel. Care
i~ must be taken that objects or materials are not pulled
into the reentry housing by the moving handrail lest
damage to the mechanism or injury to a passenger may
occur.
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Disclosure Of The Invention
This invention relates to a device which senses
abnormal forces exerted in the area of the reentry
housing, which forces are the result of an object being ~ ;
S pulled into the reentry housing by the handrail, or
~ which forces are the result of an object or the like
¦ being jammed into the reentry housing. When such
abnormal forces are detected, the escalator is turned
off and a warning alarm is sounded.
The device includes a collar that is mounted in
the mouth of the reentry housing and through which the ;~ ;-
handrail moves. An elastomeric bumper is fitted into
the collar and forms the outermost element of the
device. The bumper is the element of the device which
will ba directly contacted by anything which is on the
handrail as the latter enters the reentry housing. A
plurality of pins are mounted on the bumper and extend
through and past the collar in the direction of travel
of the handrail. The pins are operable to contact a
switch mounted in the reentry housing adjacent to the -
handrail when the bumper is sufficiently deformed by
contact with something on the handrail which is being
3 pushed ~y the handrail into the reentry housing. When
the pins contact the switch, the escalator is shut off
¦ 25 and an alarm is sounded. When the cause of the
shutdown is removed from contact with the bumper, the
latter's inherent resiliency will move the pins away
from the switch and the escalator will restart. There ;~
is also a radial pressure sensor disposed between the
bumper and the collar for detecting material which is
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carried past the bumper by the handrail. Such material
will encounter the collar and will jam against the
collar. This will cause a radially outwardly directed
force against a portion of the bumper d:isposed adjacent
~? 5 to the handrail, which radial force will be detected by
the radial pressure sensor. When this occurs, the
pressure sensor will shut the escalator off and sound
an alarm. After the jam is cleared, the escalator must
~ be manually restarted.
.?1 10 It is therefore an object of this invention to ~ ~
provide a safety device for use at an escalator ~ ~-
handrail reentry housing.
It is a further object of this invention to
?? provide a device of the character described which can
shut the escalator off upon the detection of foreign
material at the handrail reentry housing.
It is an additional object of this invention to -~
provide a device of the character described wherein
linear and radial forces imposed on the device are
detected and may serve to shut off the escalator.
These and other objects and advantages of the
invention will become more readily apparent from the
, following detailed description of a preferred
embodiment thereof when taken in conjunction with the
accompanying drawings, in which:
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;' Brief Description of the Drawings
- FIGURE l is a fragmented view of a preferred
embodiment of an escalator handrail saf?ety device
;' formed in accordance with this invention;
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FIGURE 2 is an exploded sectional view of the
device of FIGURE 1;
FIGURE 3 is a front elevational view of the bumper
component of the device of FIGURE li :
$i 5 FIGURE 4 is a front elevational view of the pin
l~ mounting component of the device;
FIGURE 5 is a sectional view taken along line 5-5 ;~
of FIGUR~ 2; and - ~;
FIGURES 6-ll are sectional views of the device and
~; lO the associated handrail showing various stages of the ~
~, device's operation. ~ -
Best Mode For Carrying Out The Invention
Referring now to the drawings, it will be noted ~ 5
that the device which is denoted generally by the ;
numeral 2 surrounds the handrail 4 as the latter enters
the reentry housing 6 (fragmentally shown in phantom
lines). The various components of the device 2 are
shown in FIGURE 2. At the handrail entry end of the
3 device 2 is a rubber bumper component 8. The bumper 8 -~ -
is elastomeric, and can be formed from a material such
3 as neoprene rubber, or the like. The bumper 8 has a ~ --
through passage lO through which the handrail 4 moves
i in the direction of the arrow A, and a rounded exposed
~ surface 12 facing the direction from which the handrail
;~ 25 advances. The downstream end of the bumper 8 is formed
~I with an annular boss 14. An annular recess 16 is -~
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formed in the downstream side of the bumper 8 about the
I boss 14. The recess 16 includes inner and outer lands
! 18 and 20, respectively. An annular base member 22 is
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disposed downstream of the bumper 8. The base 22 has a
~ profiled locking boss 24 of annular configuration which
;! iS snap fitted into the bumper recess 16 and releasably
~ held in place by the lands 18 and 20. The base 22 is
j~ 5 also formed with an internal throat 26 which telescopes
into the passage 10 of the bumper 8. The throat 26 has
-~ an axial bore 28 through which the handrail moves. A
plurality of pins 30 are mounted in the base 22 and
-3, extend downstream therefrom. A guide member 32 isdisposed downstream of the base 22 and is formed with a
counterbore 34 which telescopes over the outside of the
base 22. A boss 36 formed in the counterbore 34
telescopes into a mating portion 38 in the base 22.
~, The pins 30 extend through passages 40 in the guide 32.
The guide members 32 are preferably formed as halves of
mating pairs as shown in FIGURE 5 which are held
together by the pins 30 when the latter are telescoped
into the passages 40. Each guide member 32 has a
~ lateral opening 42 through which a roller 44 can ~-
,;~ 20 contact the moving handrail to guide the latter. The
rollers 44 are mounted on shafts 46 secured in place by
nuts 48. An outer housing or case 50, formed in mating -
halves overlies the assembly. The housing part 50 has
an upstream flange 52 the nests into an annular
l 25 marginal recess 54 in the bumper 8, and a side wall 56 - -
i that surrounds the guide 32. Inside of the housing
part 50 are lugs 58 that fit into external slots 60 in ~-
the guides 32 to secure the two parts together. The ~ ~-
~ nuts 48 are accessible through openings 62 in the
;` 30 housing 50. `~
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FIGURES 3 and 4 are front elevatic~nal views of the
bumper 8 and base 22, that show clearly the shapes of
``~ these parts. The bumper 8 and base 22 have peripheral
gaps 64 and 66, respectively, which allow the handrail
to be positioned in the passages 10 and 28,
respectively. The shape of the bumper recess 16 and
the base locking boss 24 is also clearly shown. The
location of the pins 30 in the base 22 is also shown
clearly in FIGURE 4.
Referring now to FIGURES 6-11, there is shown a
sequence of conditions which may occur at the handrail
reentry, and the manner in which these conditions will
be dealt with by the device of this invention. FIGURE
6 shows the handrail 4 moving through the device in the
direction of the arrow A. The housing part 50 engages
a stop 51 fixed to the escalator truss which holds the
housing 50 and guide 32 against movement in the
direction of the arrow A. Thus the housing 50 and
guide 32 are fixed relative to the moving handrail. ~-
The bumper 3 and base 22 can slide relative to the
~j housing 50 and guide 32, however the natural resiliency
~ of the bumper 8 and the fact that it engages the flange
;~ 52 on the fixed housing 50, will serve to hold the -~
bumper 8 and base 22 in a neutral position shown in
FIGURE 6 wherein the pins 30 are spaced apart from a
switch 31 which controls operation of the escalator
power source. If the pins 30 actuate the switch 31,
then the escalator will shut down. Additionally, there
is a radial pressure sensor 15 interposed between the ~;
outer surface of the bumper boss 14 and the inner
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surface 25 of the base 22. The pressor sensor 15 is a ;~
tape consisting inside of material which is
.. ~ electrically conductive. The conductivi.ty changes with
`~T pressure applied on the surface of the tapeO As
~3 5previously noted, as shown in FIGURE 6 there are no
;31 abnormal forces acting upon the reentrv assembly, and :
the handrail 4 is moving in a normal fashion
.~ therethrough.
In FIGURE 7, the device is viewed with a force F
acting upon the surface 12 of the bumper 8, which force
F is generated by a foreign object being pulled against
~3 the bumper 8 by the moving handrail 4. The natural
3S resiliency of the bumper 8 will create a counter force .-:
;. F1 between the bumper 8 and the fixed housing flange 52
.~ 15which biases the pins 30 away from the switch 31. So - -
.~i long as the force F is less than the biasing force F~
the pins 30 will be held away from the switch 31. Once : ~.
~ the force F exceeds the force Fl, the pins 30 will be --~
:~ moved against the switch 31 to actuate the latter,
3 20 causing the escalator to stop and causing an alarm to
sound. This condition is illustrated in FIGURE 8
wherein the net force acting upon the pins 30 is F2, -~
whereby the pins 30 are moved against the switch 31.
~ At this point the source of the pressure on the bumper
3 25 8 can be investigated and removed, whereby F becomes :- .
`. zero, and the biasing force Fl becomes the only force
acting upon the pins 30, as shown in FIGURE ~. The
elasticity of the bumper 8 thus moves the pins 30 away
from the switch 31 and the escalator is restarted, and
the alarm turned off. .:
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:i FIGURES lO and 11 illustrate operation of the
device when a foreign object or material is pulled into
the device 2 by the handrail ~. The force exerted on -~
the bumper 8 by an object at the interface between the
handrail 4 and the bumper 8 is designated by F3, and
will have an axial component and a radial component due
to its proximity to the handrail 4. When the axial
component of the force F3 overcomes the biasing force
1 of the bumper 8, the pins 30 will be moved against
the switch 31 and the alarm will sound, and the
handrail 4 will stop. If the object is in the bore 10,
~ the radial component of the force F4 will activate the -~ -
,.:'!, radial pressure sensor 15 by deforming the bumper boss
14 whereupon, when the force F4 is applied on the
sensor 15, the current i will change due to the change
of conductivity. This i5 detected by an electronic
device which in turn gives a signal that turns off the
escalator. 1- .
Once the sensor 15 has been activated, the foreign -
body can be removed from inside the device 2, and the
escalator then must be manually restarted; i.e. it will ~-~
not restart automatically as it will when only the -
switch 31 has been activated. ~ .-
j It will be readily appreciated that the device of
ij) 25 this invention provides a dual safety function in that `-~
objects impacting the reentry housing may cause the ¦
escalator to turn off, and objects which actually are
pulled into the reentry housing by the handrail will
s also turn off the escalator. In the former instance, ¦ -
the escalator will automatically restart once the -~
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anomaly is removed, and in the latter instance, the
' escalator must be manually restarted. The components
of the device are self adjustable and can conform to
~, some degree of handrail wear and dirt buildup on the
#~ 5 handrail without losing its ability to function as
intended. The component parts of the davice may all be
molded from suitable plastics and thus can be
accurately mass produced at low cost.
~i Since many changes and variations of the disclosed
, 10 embodiment of the invention may be made without
departing from the inventive concept, it is not
intended to limit the invention otherwise than as
required by the appended claims.
' What is claimed is:
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