Note: Descriptions are shown in the official language in which they were submitted.
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TELESCOPING BOLLARD WITH SCREW DRIVE
Background of the Invention
A bollard is typically employed to prevent vehicular traffic inward or past
the
point of the bollard. Accordingly, any building or structure that requires
protection may
be protected by a plurality of bollards deployed about the periphery thereof.
From a
design standpoint, bollards must be strong enough to prevent and/or
substantially slow
movement of a vehicle between the bollard and the structure to be protected.
Furthermore, periodically, vehicular access is desired and therefore the
bollards must be
designed in retractable fashion, thereby permitting vehicular travel over the
recessed
bollard.
Several retractable bollard designs are known and employ various deployment
methods including hydraulic or pressurized gas means. Hydraulic bollards are
disadvantaged by seals that sometimes deteriorate and result in a loss of
hydraulic fluid
pressure. On the other hand, bollards supported by gaseous pressure are
disadvantaged
by the loss of volume sometimes exhibited as ambient temperatures decrease. As
with a
loss of hydraulic pressure, the efficacy of the bollard comes into question as
the
supporting fluidic pressure is reduced. Furthermore, retractable bollards that
function
based on fluidic pressure must be maintained to ensure operability over
extended periods
of time.
Summary of the Invention
A bollard assembly of the present invention addresses the concerns described
above. A bollard is vertically extended or retracted by actuating a screw
drive shaft. The
shaft is supported by a tube or tower assembly that may represent a
substantially
concentric cross-section within a larger housing or tube having a larger
circumference.
The bollard is supported by a drive shaft receiver within a tower assembly,
wherein the
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screw drive shaft is actuated either manually or by a motor. The screw drive
shaft is
equipped with a drive head that accommodates security requirements by
providing a head
design that only interfaces with a socket or wrench specifically designed to
fit the unique
head design of the drive head.
Stated another way, a bollard assembly of the present invention contains an
elongated housing having a housing first end and a housing second end. A
bollard is
spaced radially inward of the housing and is substantially coextensive with
the housing,
the bollard being axially displaceable to extend from or retract within the
housing. A
tower is spaced radially inward of the bollard and extends within the housing
for support
of the bollard, the tower having a tower first end and a tower second end, and
the tower
fixed within the housing. A threaded receiver is fixed to the tower within the
housing.
A threaded drive shaft is suspended within the tower and is threadedly
received by the
threaded receiver for support of the drive shaft. A bollard carrier is fixed
to the bollard at
the housing first end, wherein the carrier is also fixed to the threaded drive
shaft for
support of the bollard upon vertical displacement of the bollard. Upon
rotation of the
threaded drive shaft, vertical displacement of the bollard is established as
the threaded
drive shaft and the bollard move in unison.
Brief Description of the Figures
Figure 1 is sectional view of a manually operated bollard assembly in
accordance with
the present invention.
Figure 2 is a sectional view and a side view of a bollard carrier in
accordance with the
present invention.
Figures 3a and 3b are a top and side view of a bollard housing flange in
accordance with
the present invention.
Figures 4a and 4b are a top and side view of an access flange in accordance
with the
present invention.
Figure 5 illustrates a bollard assembly containing a compressed spring for
support of a
bollard.
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Figure 6 is a top view of a socket designed to fit a drive shaft drive head in
accordance
with the present invention.
Figure 7 is a sectional view of a travel stop flange having a cylindrical lock
placed
proximate to a flat of the travel stop flange.
Figure 8 is a sectional view illustrating the prevention of rotation of the
travel stop flange
when engaged with the cylindrical lock.
Figure 9 is a sectional view of a bollard assembly having a bollard in an
extended
position.
Figure 10 is a sectional view of a bollard assembly having a bollard in a
retracted
position.
Figure 11 is a sectional view of a motor driven bollard assembly in accordance
with the
present invention.
Figures 12 and 14 show the lower end of the bollard assembly of Figure 11.
Figure 13 is a cross-section taken at line 13-13 of Figure 12.
Detailed Description of the Present Invention
As shown in the figures, the present invention provides, in one embodiment, a
bollard assembly 1 containing an improved retractable bollard 2 operable on a
screw
drive shaft. A bollard housing or tube 4 contains the bollard 2 for slidable
and retractable
engagement therein. The housing 4 contains a first end 6 and a second end 8. A
tower
assembly 10 is substantially concentrically disposed within the bollard
housing 4 from
the first end 6 to the second end 8, thereby providing a support or pedestal
for the bollard
2. A tower tube 12 is substantially coextensive with the tower assembly 10 and
connects
a first tower assembly end 14 with a second tower assembly end 16.
A bollard housing base flange 18 is welded or otherwise fixed to the second
end 8
of the housing 4 thereby providing a support base for the entire bollard
assembly 1. If
desired, the housing base flange 18 may include orifices for drainage of any
moisture that
accumulates within the bollard assembly 1. As described above, the tower tube
12 is
welded or otherwise fixed to the base flange 18, at second end 8, thereby
fixing the tower
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within the housing 4. A bollard housing flange 20 is welded or otherwise fixed
to the
first end 6 of the housing 4, thereby providing a compartment or recess 22 for
packaging
of upper members (further described below) of the bollard assembly 1. As shown
in the
figures, at least one lifting eye 24 and in the embodiment shown, a plurality
of lifting
eyes 24 may be welded or otherwise fixed to the base flange 18 and/or the
bollard
housing flange 20, thereby facilitating movement of the bollard assembly 1 by
attachment
to one or more of the lifting eyes 24.
An inner circumferential wall 26 of the housing 4 is defined by the housing 4,
and
is substantially coextensive with the bollard assembly 1. The bollard 2 is
spaced radially
inwardly of the inner wall 26. A compression spring 28 is spaced radially
inwardly of the
bollard 2 and substantially constrained along the length of the bollard 2
thereby
supporting at least part of the load of the bollard 2 as it extends from the
housing 4. The
tower assembly 10 is spaced radially inwardly from the compression spring 28,
or
encased by the compression spring 28. As described below, a threaded drive
shaft 30 is
threadedly received within the tower assembly 10 thereby providing extension
and
retraction of the bollard 10. It will be appreciated that the drive shaft 30
is preferably,
although not necessarily, threaded for most if not all of its length to
facilitate a maximum
height of the bollard 2 once it is fully extended. A thrust bearing 29 is
shown as
juxtaposed to the nut 48 as described herein. Stated another way, the thrust
bearing 29 is
located intermediate the nut 48 and the travel stop flange 42 thereby
absorbing the axial
load within the shaft 30.
A drive shaft receiver or receiver assembly 32 is fixed to the top end 14 of
the
tower assembly 10, and contains the constituents described immediately
hereafter. An
annular nut flange base 34 is welded or otherwise fixed near the tower end 14.
An
annular nut flange 36 is bolted to nut flange base 34 thereby providing a
threaded female
receiver for extension and retraction of the threaded drive shaft 30. Nut
flange bolts 39
secure nut flange 36 against nut flange base 34. A nut 38 is fixed to nut
flange 36 for
threaded receipt of the drive shaft 30. Nut 38 may be fixed to nut flange 36
by threading
the exterior as well as the interior of the nut 38, and providing a mated
thread on the
annulus of the nut flange 36. Nut 38 may then simply be threadedly received by
nut
flange 36. Other methods of fixing nut 38 to nut flange 36 known to those of
ordinary
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skill are also contemplated. A lubricant reservoir 40 is positioned between
the first end
14 of the tower 12 and the nut 38, in coaxial relation with the tower 12,
wherein portions
of the threaded drive shaft 30 traverse through the reservoir 40 prior to
passing through
the nut 38, thereby ensuring proper lubrication of the drive shaft as it is
extended or
retracted. A travel stop flange 42 is fixed at an upper end 44 of the drive
shaft 30 to
terminate movement of the drive shaft 30 once the flange 42 contacts the
reservoir 40
during retraction of the bollard 2. A cylindrical spacer 46 rests upon nut
flange 36 to
locate the bollard 2 in the housing 4 against the stop flange 42.
A drive head 48 is integral to and fixed atop the drive shaft 30 thereby
providing a
manual means to drive the shaft, either by drill or by ratchet for example. As
shown in
The drive head 48 may be uniquely designed/machined to accommodate any
desirable
socket not commonly available to the general public. Accordingly, a mating
socket for
use with any suitable wrench is also manufactured as part of the overall
bollard system.
One or more vents 50 are juxtaposed to drive head 48, although the vents may
be located
in any other effective area, and are employed to vent air as it is displaced
within bollard
housing 4 during movement of the drive 30. The vents additionally function to
provide
conduits to the reservoir 40, thereby facilitating the replenishment of the
lubricant within
the reservoir 40, with lubricating compound for example, without requiring
dismantling
of the upper area of the bollard assembly 1.
Again referring to the bollard 2, the bollard 2 is provided with several
features
thereby providing operable advantage as described below. As shown in Figure
12, a
bottom end 52 of the bollard 2 is formed with a first guide ring 54 welded or
otherwise
fixed thereto, the first guide ring 54 having a diameter slightly larger than
a majority of
the bollard 2. A second guide ring 56, having substantially the same diameter
as the first
guide ring 54, is welded or otherwise fixed upwardly on the bollard 2, about
one-third of
its relative length. A first notch 58 is formed within the first ring 54,
thereby providing a
mate for an associated key described below. A second notch 60 is formed within
the
second ring 56, in linear relation with first notch 58 and substantially
parallel to a
longitudinal axis of assembly 1, whereby notches 58 and 60 are oriented in a
substantially
equivalent angular displacement about the circumference of bollard 2. A
polymeric
bushing or bearing 62 provides a shell about the bollard 2, albeit the shell
is truncated at
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each point that each notch circumferentially begins and ends. Accordingly, a
first half 64
of the bearing 62, and a second half 66 of the bearing 62, are mated together
to form a
bearing interface between the inner wall 26 and the bollard 2, with an arcuate
length
equal to that of each guide ring 54 and 56. The result is a linear arrangement
of the
notches 58 and 60 to provide a gap 61 formed between first and second halves
64 and 66,
wherein the gap 61 has a radial length A and an arcuate length B.
A key 68 is formed along the length of the inner wall 26 and defines a linear
ridge
extending along the same arcuate orientation across the length of the bollard
housing 4.
It will be appreciated that the gap 61 and the key 68 mate to form a lock and
key
relationship whereby rotation of the bollard is thereby prevented. Stated
another way,
gap 61 and key 68 have substantially the same radial length A and
substantially the same
arcuate length B whereby mating of the two results in a bollard that moves in
a vertical or
axially parallel direction only.
Upper members of the bollard assembly 1 may be employed as in the following
description. A housing flange 70 forms an upper periphery about the bollard
assembly 1.
An annular access flange 72 is fixed within recess 22 radially inward of
housing flange
70, and provides a watertight seal about drive shaft receiver assembly 32 when
combined
with a cap as described below. The flange 72 represents the majority of the
surface area
of the bollard assembly 1. Accordingly, the top surface may be scored, etched,
die-cast
to form a pattern, or basically formed with a non-skid surface if desired. A
plurality of
tamper-proof bolts 74, again machined to complement a tool dedicated to remove
the
bolts 74, are used to fasten the access flange 72 within the compartment 22
and against
the housing flange 70, thereby covering the receiver assembly 32. A plurality
of orifices
75 are provided within flange 70 for receipt of a corresponding number of
bolts 74. A
first access flange seal or o-ring 76 may be employed about the periphery of
the access
flange 72, to seal the arcuate interface between the access flange 72 and the
housing
flange 70. A bollard bearing 78 is positioned radially inwardly of access
flange 72, for
guidance of bollard 2 as it extends or retracts within the housing 4. An
annulus or bollard
portal 80 within the annular access flange 72 fits flushly against the bollard
2 as it
traverses therethrough, and permits passage of the bollard 2 as it is extended
or retracted
from the housing 4.
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An upper area portion 82 of the bollard 2 is designed to provide functional
access
to the drive mechanism of the bollard assembly 1. As shown in the Figures, an
annular
carrier 84 is fit within the top of the bollard 2 and is substantially
circumferentially
coextensive with the bollard 2. The carrier 84 is fixed to the drive shaft 30
by a recess
formed within the carrier that houses the top end of the drive shaft 30. An o-
ring or seal
85 seals the interface between the carrier 84 and an inner wall of the bollard
2. An
annular upper bollard flange 86 provides a pedestal on bollard 2 for flush
communication
with the carrier 84. A plurality of fasteners 88 may be provided to fasten the
carrier 84
against the bollard flange 86. A plurality of threaded orifices corresponding
to the
number of fasteners 88 may be provided for threaded receipt of the fasteners
88. A
carrier annulus or recess 90 is defined within the annular carrier 84 for
seating and
operation of the drive shaft 30. The lock bolt or drive head 48 is integrally
and operably
connected to drive shaft 30 within the annulus 90, constituting the top of the
drive shaft
30 for engagement with a complementary wrench. Furthermore, the drive head 48
basically forms an interference fit of sorts thereby retaining the drive shaft
within the
carrier 84 as the drive shaft is rotated to extend bollard 2, also connected
to the carrier 84.
As the drive shaft 30 is rotated by rotation of drive head 48, the carrier 84,
fixed to the It
will be appreciated that with regard to security, the lock bolt 48 may feature
a unique fit
or pattern that is complemented by a corresponding wrench not available to the
general
public. As shown in the drawings, a cover or cap seal 96 is positioned over
lock bolt 48,
and when fastened in place by bolt 98, the drive head or lock bolt 48 is
thereby provided
with a watertight seal. A seal 100 surrounds the periphery of the cap 96
enhancing the
seal of the cap 96.
In operation, the bollard assembly 1 is installed to be level and flush with
the
substrate surrounding the assembly 1. Accordingly, typical substrates include
black top
or concrete. To extend the bollard 2, the cap 96 is removed to reveal drive
head 48.
Drive head 48 is engaged with a socket and wrench designed to fit the specific
design of
the drive head 48, as determined by customer requirements. The drive head 48
is rotated
to upwardly extend the bollard 2, or if the bollard 2 is already extended, the
drive head 48
may also be retracted to a position level with the road. As shown in Figures 9
and 10, the
bollard 2 is carried upward in the housing 4 as the drive shaft 30 traverses
upwardly
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through the receiver assembly 32. Stated another way, upon rotation of the
drive nut 48,
the bollard 2 is lifted as the drive shaft 30 is driven upwardly through the
bollard portal
80 along with the bollard 2.
In another embodiment shown in Figure 11, an optional reversible electric
motor
102 (schematically represented) may be bolted to a carrier flange 104. A first
plurality of
carrier bolts 106 are threadedly received through a corresponding number of
holes in the
carrier flange 104, and then threadedly received within the housing of the
motor 102. An
annular motor mount 108 is welded or otherwise fixed to the inside wall 26 of
the bollard
2. A second plurality of carrier bolts 110 are threadedly received through a
corresponding number of holes in the carrier flange 104, and then threadedly
received
within the motor mount 108 for additional support of the motor 102. Emergency
cap 112,
fit within a recess 114 within the carrier flange 104, may be removed in the
event of a
power failure where bollard access 2 is required. Accordingly, at least one
bolt 116 is
employed to fasten cap 112 to the carrier flange 104. It will be appreciated
that other
features numbered as in the first embodiment essentially function in the same
way unless
otherwise indicated. A power cord 118 is coiled about tower 12 and is then
routed from
the bollard assembly 1 to a conduit tube leading to a control box (not shown).
If desired,
the controls to the motor 102 may be programmed to work only when an access
code is
determined via radio frequency identification or any other type of electronic
and/or
remote identification, for example. A first coupler flange 126 is located on
the motor
armature shaft and is bolted to a second coupler flange 128 for translation of
energy from
the motor 102 to the drive shaft 30.
Any embodiment of the present invention may optionally employ a radio
frequency identification device for access and/or identification of a breach
of the cover
96, 112 of the bollard assembly 1. Radio frequency identification provides
ongoing
transmission and reception of a signal that when interrupted indicates a
breach of the
bollard assembly 1. Further, as shown in Figure 11, vents 124 may be arranged
in an
oblique fashion along the sides of housing 4 within the bollard 2, thereby
venting air
displaced during operation of the bollard 2. The wire conduit may also be
utilized to vent
the air displaced during operation of the bollard assembly 1. In any
embodiment,
removal of the cap or cover 96, 112 provides access to the drive head 48
whereby a drill
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with the properly designed socket may be employed to deploy the bollard 2 in a
matter of
seconds.
An optional abrasive liner may be fixed between the outside diameter of the
tower
12 and the compression spring 28, thereby inhibiting penetration of the
bollard 2, by a
saw for example. The liner may be made from hardened steel or any other
hardened
and/or abrasive material in a known manner.
As shown in Figures 7 and 8, an optional manual cylindrical keyed lock 132
extends radially inwardly through the bollard 2, whereby a lock cylinder 133
extends into
a flat 135 of the travel stop flange 42. This aspect of the invention may be
employed to
provide additional security relative to a manually operated bollard assembly
1, that is one
driven by a drill or hand operated wrench. A first locking orifice 134 is
provided in the
housing 4, for passage of the lock 132. A second locking orifice 136 is
provided in tower
12, in coaxial relation to the first orifice 134, for passage of the lock 132.
When
implemented, the stop flange 42 is prevented from rotation by interference
with the flat
135 and the cylinder 133. Accordingly, drive shaft 30, fixed to flange 42, is
also
prevented from rotating and therefore unauthorized retraction of the bollard 2
is inhibited.
See Figure 8 illustrating the same.
The structure described above is formed from metallic components. The metallic
components of the present invention may be die-cast, machined, or otherwise
metal-
formed as known in the art. The size of the bollard assembly 1 and the
relative sizes of
the associated components may be varied and determined as per design
requirements.
The motor 102 and the attached circuitry, including the radio frequency
identification
circuitry, may be provided by known suppliers, or manufactured in a known
manner.
Metallic components of the present invention may also be interchanged with
polymeric or
tough composite materials so long as the material is suitably tough for the
respective
function served.
In yet another aspect of the invention, as shown in Figure 6, a bollard system
as
described above includes a socket or tool 120. As further shown in the
figures, a
plurality of slots 121 are defined within the carrier 84 and mate with the
tool 120 to
remove the carrier 84 from the top of the bollard 2. As shown in Figure 5, the
carrier 84
may be threadedly received within the bollard 2. Tool 120 is designed to
complement the
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placement of the slots 121 within the carrier 84. Accordingly, as shown in
Figure 6, the
tool 120 may complement a carrier 84 having three slots spaced 115 degrees,
118
degrees, and 127 degrees of arcuate length from an adjoining slot.
In sum, the present invention includes a bollard assembly containing an
an elongated housing; a bollard spaced radially inward of the housing and
axially
displaceable therein; a threaded drive shaft receiver centrally fixed within
the housing for
threaded reception of a threaded drive shaft; and a threaded drive shaft
suspended within
the housing and threadedly received by the receiver, the drive shaft operably
connected to
the bollard, whereby rotation of the drive shaft establishes vertical
displacement of the
drive shaft and the bollard.
It will be understood that the foregoing description of an embodiment of the
present invention is for illustrative purposes only. As such, the various
structural and
operational features herein disclosed are susceptible to a number of
modifications
commensurate with the abilities of one of ordinary skill in the art, none of
which departs
from the scope of the present invention as defined in the appended claims.
