Note: Descriptions are shown in the official language in which they were submitted.
~ 1176185
SPEC,IFICATION
BACKGROUND OF THE INVENTION
The present invention relates to an improved
hydraulic elevator construction.
In conventional hydraulic elevator svstems, an
hydraulic jack is centrally located in the hoistway, and
the plunger of the jack is attached to the bottom frame of
the elevator cab to su?port the cab from below. The jack
cylinder is sunk into the ground to a depth sufficient to
permit the elevator cab to be lowered to ground (or basement)
13 floor level when the plun~er is fully retracted.
In this type of installation, the height of desired
elevator cab travel determlnes the retracted length of the
piston and cylinder combination, and thus determines the depth
to which the cylinder must be sunk into the ground. ~ hole
1~ mus. ~e drilled in'_o the ~round to receive the cylinder in
proper alisnment with the hoistway, and normallv a casing
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needs to be installed to line the hole, both of which
are expensive operations. Moreover, deployment of the
cylinder below ground itself creates problems, for example
relating to corrosion, electrolysis, and inspection.
Corrosion of the cylinder may result in a sudden loss
of fluid pressure in the cylinder, thereby rendering the
elevator inoperable and necessitating extensive and costly
repairs.
Several arrangements have been proposed to
overcome the problem and expense of sinking an hydraulic
cylinder into the ground. In one type of arrangement,
the upper portion of the car frame is extended to one
side of the cab and a conventional or telescoping hydraulic
cylinder, which may be above ground or, where longer lifting
distances are required, partially sunk into the ground, is
attached to the frame extension. This arrangement produces
hish eccentric loads ~ith resultant structural and service
demands.
In another arrangement, the car frame is extended
to either side of the cab, and a pair of above-ground or
partially sunken jack cylinders are arranged laterally to
either side of the elevator cab. This arrangement is more
expensive, takes longer to install, and increases service
demands.
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My prior U.S. patent No. 3,954,157 discloses a
novel hydraulic elevator installation in which the depth
of the hole required to receive the jack plunger and
cylinder is reduced, as compared with conventional designs,
by at least the ~eight of the elevator car. The jack
plunger is fixed in the elevator hoistway, and the jack
cylinder is disposed over the plunger. The jack cylinder
extends up through the elevator cab in the door return column
and forms part of the elevator cab lifting frame. With
the jack in its fully retracted position, such that the
cab is ground floor level, approximately 12 feet of jack
- cylinder and plunger are disposed above ground in the
door return column. As a result, as opposed to conven-
tior,al designs where the entire jack is disposed below
the cab, in many installations no jack hole is required,
and in installations requiring a longer jacX stroke the
hole depth is reduced by the length of jack disposed in
the door return column.
In the construction disclosed in ~.S. patent No.
3,954,157, the jack extends up through the cab in the vicinity
of the center of gravit~y. As opposed to side mounted,
single cylinder arrangements such as described above,
the cab may be supported with a reduced cantilever
effect and thus avoids high eccentric structural 102ds.
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single cylinder may therefore readily be employed, or
if desired a pair of cylinders, one on each side attached
simllar to the mounting disclosed in U.S. patent No.
3,954,157, may be used.
S SUMMARY OF TH~ INVENTION
The present invention is a novel hydraulic elevator
construction in which, similar to the elevator shown and
described in my U.S. patent No. 3,954,157, the cab may be
supported by a single hydraulic jack disposed in the hoistway,
the required depth of the hole for receiving the jack is
reduced by at least the height of the elevator cab, and the
jack may be centrally disposed relative to the center of
gravity of the cab to reduce or eliminate eccentric loading.
More particularly, in the preferred embodiment of
the invention an hydraulic elevator installation has a frame
which includes at least one overhead frame member, for
exarple a cross-beam, which is capable of carrying the weight
of the car. An hydraulic jack has a cylinder which is fixedly
mounted in a vertical position in the hoistway, and a plunger
t~hich extends upwardly from the cylinder through the car to
engage the overhead cross-beam, such that the cross-beam,
znd thereby the elevator cab, is carried by the plunger. The
bottom of the elevator caD is provided with an opening for
receivins t;ee ?lunger anc also for receiving the cylinder
when the jack is in the retracted position. Preferably, the
,zck is disposed in the ~oor return column of the elevator cab,
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but it may be disposed at other locations within the cab.
In the latter case, the cylinder and plunger unit are
preferably enclosed within the elevator cab to protect
passengers or objects from the relative motion between the
stationary cylinder and the moving passenger compartment.
A telescoping cylinder unit may also readily be employed
with the present invention, which can further reduce or
eliminate the required hole depth for the jack.
Where the jack extends up through the forward
portion of the cab, for example in the door return column,
and the cab-supporting frame members are disposed near the
front of the cab, the conventional elevator rail guides may
readily be mounted on the frame, to either side of the cab,
and will be disposed in the front portion of the hoistway.
The cooperating tracks are thus also positioned in the forward
portion of the hoistway. This facilitates the utilization of
the im?roved rail mounting system described in my prior U.S.
patent No. 4,948,358.
In an elevator construction in accordance with
2Q the present invention, standard or telescoping jacks may be
mounted on the hoistway floor or, if necessary, below ground,
using conventional upright installations. Common components
such as bolsters, guide shoes, and pit eauipment, may be
used such that s?ecialized inventory items are not required.
Also, a conventional elevator cab and frame may be empioyed,
such that the frame may be broken down for shipping and
hanaling in the field. As installed, in most cases the top
of -:.e cvlinder is well above the level of the tank so a
ci-ect return can be installed to handle leakage.
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Thus, the invention does not re~uire the use of
specialized structures, and is easy to install and maintain.
The hydraulic lift configuration eliminates totally or at
least substantially reduces the eccentric loading by
positioning the lifting point within the confines of the
elevator cab. At the same time, the depth of the jack hole
is reduced by approximately 12 feet in every installation,
so that in some installations no hole is required at all,
and by employing a telescoping cylinder ~ack the required
hole depth may be reduced further.
For a better understanding of the invention,
reference is made to the following detailed description
of the preferred embodiments, taken in conjunction with
the drawings accompanying the application.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a front view, partially in section,
of an hydraulic elevator installation in accordance with
the invention;
Figure 2 is a top view of the hydraulic elevator
ccnstruction shown in Figure l;
Figure 3 is a sectional view, taken through lines
3-3 of Figure 1; and
Figure 4 is a top sectional view of an alternative
e~odl~.ent o~^ elevator construction in accordance with the
presen. invention.
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DETAILED DESCRIPTION OF THE PREFERRED E~ODI~ENTS
In the embodiment shown in Figs. 1~3, the cab frame
includes a pair of vertically arranged stile members 14 and
16, a pair of overhead cross-beams 18 and 20, and bolster
members 22 and 24. The bolster members 22 and 24 support an
elevator platform 12. The frame members 14, 16, 18, 20, 22
and 24 may also support sidewalls, a ceiling, and an elevator
cab door (not shown in Figs. 1-3).
In the frame shown, each of the frame members 14-24
is a C-shaped structural beam bolted or welded together. Other
types of frames, however, ~hich include an overhead frame
member or members capable of carrying the weight of the cab,
ma~ be utilized.
The elevator cab 10 is supported by an hydraulic
1~ jack in the form of a telescoping cylinder arrangement 26.
The telescoping cylinder 26 may be constructed in accordance
with the disclosure in my U.S. patent No. 4,201,0~3; however,
other constructions of telescoping cylinders, or conventional,
non-telescoping jacks, may be used. The elevator platform 12
has an opening 28 therein large enoush to receive the outer-
most cylinder 30 of the telescoping jack ~6. Cylinder 30
should be freely slidable in hole 28 in the longitudinal
direction. Hole 28 may be sized to provide clearance between
the platform 12 and cvlinder 30, or may engage cylinaer 30
to ?rovice freedom of longitudi!lal movement bu, a lateral
bearing surface between the cab and cylinder.
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The plunser 32 of the jack 26 extends up through
the elevator cab and engages the cross-beams 18 and 20 to
support the weight of the elevator. As shown, the plunger 32
is supported between the spaced beams 18 and 20 by a locating
S crosshead 34 secured in a slot cut into the upper end of the
plunger 32. However, other plunger-to-cab frame connections
may be employed, for example connections similar to those used
in inst211ations where the plunger 32 is attached to the bottom
of the cab frame. Also, while the plunger 32 is shown as
10 coupled to the beams 18 and 20, the plunger may be attached to
other overhead frame members capable of supporting the elevator
cab.
In operation, when the elevator cab 10 is lowered
to the ground Gr basement floor (i.e. the lowest floor),
1~ the plunger 32 is retracted into the telescoping cylinders
29 and 30 of the hydraulic jack 26. The elevator cab 10
slides down over the cylinder 30 of the jack 26, such that
the cylinders 29 and 30 and the plunger 32 are disposed
within the confines of the elevator cab 10. ~hen the elevator
20 cab rises, cylinder 30 remains stationary and the telescoping
cylinder 29, the plunger 32 and the elevator cab rise. At
the upper end of the plunger stroke, the elevator cab 10 is
disposed above the outer cylinder 30, such that the cylinder 30
no longer is disposed within the hole 28. As sho~Y-n in ~iss.
2~ 1-3, a ?rotective sleeve 33 is mounted in the elevator cab 10
about the jack 26 to protect passengers and freight from injury
resultant from the relative motion bet~een cylinders 30 and 29
and the c~b 10.
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Figure 4 discloses the preferred location of the
hydraulic liftlng mechanism, which is shown in Fig. 4 as a
conventional (i.e. non-telescoping) hydraulic jack 26'. The
elevator cab 10' is disposed in a hoistway 50. Rail guides 52
are disposed to either side of the cab 10-', and received in
cooperating tracks 54 mounted to the hoistway walls 51. Rail
guides 52 may be bolted or welded to frame member 14' and 16',
or otherwise suitably attached to the frame. The guides 52
are shown as U-shaped channels, however guides of the roller-type
may be employed. Each track 54 is preferably mounted to the
hoistway walls 51 utilizing rail mounting brackets of the type
disclosed in my prior U.S. patent No. 3,948,358. The elevator
cab 10' includes a platform 12', sidewalls ~0 and a door return
column 42, which conventionally houses an operating panel and
1; other equipment. Door 44 is slidably disposed in a conventional
manner in the front end of the elevator cab 10' to the side of
the door return column 42.
The platform 12' is supported on the frame, which
lncludes stile members 14' and 16', and lower bolster members
22' and 24'. In this manner, the plunger 32l extends upwardly
through the door return column 42 and engages the overhead
cross-beams or other overhead cross-members (not shown) close
to the center of gravity of the cab 10'.
The foregoing represents the preferred embodiments
2_ of the invention. Variations and modifications of the disclosed
embodiments will be apparent to persons skilled in the art while
em,?loying the inventive concepts disclosed herein. All such
modifications and variations are intended to be within the
scope of the invention as defined in the following claims.
